Yasmin Khan

PC  Yasmin "Yaz" Khan was a companion of the Thirteenth Doctor and a junior police officer with Hallamshire Police. She lived in Flat 34 of the Park Hill estate in Sheffield with her parents Hakim and Najia, and her sister Sonya. She was a practising Muslim of Pakistani descent.

As part of Team TARDIS, Yaz often made use of her investigative skills to help the Doctor solve problems; versatile in the area, Yaz either questioned people for information or investigated items of interest. In addition, Yaz also had training in helping reassure and calm victims and survivors of horrible incidents. This often came in handy during adventures where they needed to gain the confidence and trust of people who could help out.

Early life
Yasmin was born to Hakim and Najia Khan (TV: Arachnids in the UK) in early 1999. (COMIC: A New Beginning; PROSE: The Secret in Vault 13, Dr. Thirteenth) She had a younger sister named Sonya, with whom she did not get along. (TV: Arachnids in the UK)

When she was little, Yaz begged her parents to get a pet rabbit but was not allowed one because Hakim was allergic to animal fur. Instead she was given a cuddly toy named Mister Hoppy. (PROSE: The Secret in Vault 13)

Education
As a child, Yasmin attended Redlands Primary school alongside Ryan Sinclair. (TV: The Woman Who Fell to Earth) She was known to be attending primary school by at least 2004. (PROSE: Time Lapse) Yasmin was placed in a class named after Rosa Parks. (TV: Rosa) Her best friend at primary school was Poppy Hillman. Around 2008, when they both started attending secondary school, their friendship ended after Taylor Grant called Yaz an "Islamist terrorist". (PROSE: The Good Doctor) When Yaz was twelve years old, she was best friends with another girl named Aisha and went on a school camping trip with her. (PROSE: The Secret in Vault 13) In Year 10, she sneaked into Danny Biswas' house through the window. (TV: Rosa)

Yasmin studied criminology, and one of her lecturers on the subject once said that "unique was where answers lived". (PROSE: The Shadow Passes)

Yasmin was also bullied by Izzy Flint, who left Yasmin feeling afraid for a whole year. (TV: The Witchfinders) When things got particularly difficult, to the extent that it affected her grades at school, Yaz ran away from home feeling that her parents did not understand her problems. Convinced that she was "going to do something stupid", Sonya reported her missing. Yaz was found on the moors by PC Anita Patel, who convinced her to face her problems by offering her a compromise: "Moments change. Look me up in three years. If I'm wrong, I'll give you 50 quid. But if I'm right, you owe me 50p". (TV: Can You Hear Me?)

Work with Hallamshire Police
Around 2016, inspired by Anita Patel, Yasmin joined Hallamshire Police as a junior officer. (TV: The Woman Who Fell to Earth) Her police officer training included learning about measures to help children feel safe in stressful circumstances. (TV: It Takes You Away)

Yasmin encountered the effects of racism in the 21st century. She often had racial slurs like "paki" directed at her during her work as a police officer, and she was labelled a terrorist due to her Muslim faith. (TV: Rosa) She was sometimes stationed at the city centre on a Friday night, (WC: Case File Two) and dealt with many domestic violence cases. (PROSE: Gatecrashers)

Though she hoped for more high-stakes assignments, (TV: The Woman Who Fell to Earth) Yaz was dedicated to her responsibilities as a police officer, which she took seriously. As she did not pursue a social life outside of work, Yaz's family considered her to be "married to her job". (TV: Arachnids in the UK)

Meeting the Doctor
As a trainee on second-year probation, Yaz was often sent by her superior, Ramesh Sunder, to deal with small-time petty disputes. After vocalising her need for something more, she was sent to investigate an unidentified object in the Peaks outside Sheffield. There, Yaz found the caller was Ryan Sinclair, whom she recognised from school. Ryan insisted the call was not a prank and, though Yasmin didn't initially believe him, touching the cold object led to her doing so.

After Ryan received a call from his grandmother, Grace, Yaz accompanied him to check on her, finding her train under attack from a mysterious creature. There, she encountered the Thirteenth Doctor. Yasmin, along with Ryan, Grace and the latter's husband Graham O'Brien, helped the Doctor investigate and stop the pod's occupant, a Stenza named Tim Shaw, from abducting Karl Wright. After Grace died while disabling the coil, Yasmin attended her funeral.

Yasmin later helped the Doctor construct a teleporter to get her to her TARDIS. Though meant to stay whilst she left, Yasmin, Ryan and Graham were also teleported into deep space with her. (TV: The Woman Who Fell to Earth)

Believing the pair to be bonuses in the Rally of the Twelve Galaxies, Epzo scooped Yasmin and the Doctor out of deep space and transported them aboard his ship - the Cerebos. Yaz awoke in a MediPod, stepping out to find the Doctor preparing to jettison the back of the ship, initiating a speed boost which caused them to crash onto the surface of Desolation.

On Desolation, she found Ryan and Graham, who had been similarly saved by Angstrom, Epzo's rival in what would become the final stage of the rally. The rivals, with the Doctor and her friends in tow, were tasked by Ilin, master of the rally, to race across the planet; the first to reach the finish line at the Ghost Monument would win 3.2 million krin and salvation from planet's hostile surface. The Doctor discovered that the Ghost Monument was, in fact, her TARDIS, phasing in and out of reality. After the Doctor stabilised the TARDIS, Yasmin entered it for the first time and the Doctor attempted to take them home. (TV: The Ghost Monument)

Trying to return home
Attempting to land the TARDIS back in 21st century Sheffield, the Doctor failed several times to bring Yasmin home. When the TARDIS latched onto nearby artron energy and they landed 1955 Montgomery, Alabama, Yaz was excited to begin her first adventure in the past and was astonished to meet Rosa Parks. In Slim's Bar and the Sahara Springs Motel, she recounted the famous historical event of Parks refusing to give up her seat to a white passenger, starting the Montgomery Bus Boycott.

She also endured many of the effects of racial segregation in the 1950s. She was misidentified as Mexican instead of a British woman of Pakistani descent and this caused her to be denied service at the bar and she had to discretely enter the motel room through the back window. However, she was permitted to enter the buses in Montgomery through the front door and sit in the "white-only" section, unlike the black people who had to sit at the back of the bus. She remarked that she was unsure in her place in Montgomery due to the lack of citizens with Pakistani heritage.

Attempting to stop Krasko's plans to alter history, Yasmin and the Doctor made sure Rosa Parks left work as a seamstress on time by giving her their clothes to mend. Yasmin chatted with Parks about her life, and the latter was surprised to hear that Yaz was permitted to be a police officer.

By making sure that the bus was crowded enough that Parks's moment of defiance could happen, the Doctor, Graham, and Yaz reluctantly became the three extra "white" passengers that required Parks to move back. The three, as well as Ryan, then witnessed Parks's historic arrest. Back in the TARDIS, the Doctor explained how Parks would be commemorated in the future, and Yasmin saw Asteroid 284996, also named Rosaparks, in space. (TV: Rosa)

Returning home
Yaz returned home to Sheffield in 2018 just half an hour after she had been transported into deep space. Noticing the Doctor's sadness at the prospect of travelling alone, she invited her to tea at her family's flat, along with Ryan and Graham. There, Hakim and Sonya teased Yaz who rarely brought friends home. However, her mother rang Yaz shortly after, asking her to pick her up and to not tell her father about it.

Claiming she was taking a parcel to Najia, she left her father, sister, Ryan and the Doctor and drove to Jack Robertson's luxury hotel. She seemed impressed, but her mother confided that she had just lost her job as general manager. Robertson then appeared and had Kevin hold Yaz and Najia at gunpoint for trespassing, to which Yaz protested, asserting that they had no right and demanding to know why her mother had been sacked.

Yaz and Najia were shown a hotel room full of cobwebs, which no-one could explain. Left in the room, she was phoned by the Doctor, and the TARDIS team regrouped in the lobby, joined by Najia and Jade McIntyre. Her mother embarrassed Yaz when asking if she and the Doctor were in a relationship though was more irritated when asked the same of Ryan.

After the giant spiders were contained, she offered to get her family their bread, promising her mother she would tell her the truth about the Doctor when she returned. She decided to stay travelling in the TARDIS with the Doctor, a decision also followed by Ryan and Graham. (TV: Arachnids in the UK)

Team TARDIS
Team TARDIS found themselves on Seffilun 27 in the 67th century. When they unearthed a sonic mine that the Doctor could not disable, all four were rendered unconscious. They were recovered by the medical ship Tsuranga and Yaz woke up after several days. Bound to Resus One, the ship was attacked by a Pting that Yaz helped the Doctor defeat. (TV: The Tsuranga Conundrum)

Yaz and Team TARDIS travelled to the planet Gatan, arriving in the City of Radiant Stone in the midst of war. A lost young girl called Tondi took a shine to Yaz as she promised to help her find her mother while the Doctor, Graham, and Ryan investigated the area to see why it was destroyed. When two super-soldiers called Tumat and Kraytos appeared, Yaz ran with Tondi despite wanting to help the Doctor. Safely out of the fighting, Yaz and Tondi hid from a group of drunken revellers, celebrating the collapse of society, as they attempted to find Tondi's Aunt Vela instead. Yaz eventually had to use her powers of command presence to intimidate a crook into leaving an innocent old man alone and quickly found Vela, who revealed that Tondi's mother had died. With the Doctor eventually returning to Gatan, she reunited with Yaz as she helped lure Tumat and Kraytos into a teleport pad, forcing them to re-emerge in the same place as one combined being. With the new Chimera stopping the war, Yaz and Tondi visited The Freedom Thoughtcasting Network where the battle was being broadcast from and used Tondi's painful memories to shut down the operation before Yaz had to go on her way. (COMIC: The Warmonger)

On Proxima Ceti, Yasmin witnessed the Doctor outwitting carnivorous chessmen. (PROSE: The Secret in Vault 13)

For Yasmin's birthday, the Doctor brought her a Sontaran Frosted Boom Cake from Sontar, two zeppelins from the London Blitz and a candelabra from Paris. (PROSE: Dr. Thirteenth)

The Doctor and her team were tasked with preventing the Genesis Seed stored in the secret Vault 13 within the Galactic Seed Vault from falling into the hands of Nightshade. (PROSE: The Secret in Vault 13)

Yaz returned home to celebrate her grandmother Umbreen's birthday. Umbreen told Yaz she was her favourite granddaughter and gave her a watch with a shattered face that was precious to her. However, Umbreen did not elaborate on the sentimental value of the watch, nor the lifelong accomplishments she spoke of. This caused Yaz to grow curious and she asked the Doctor to take her to see Umbreen when she was younger.

With the watch being put into the telepathic circuits, the TARDIS took the Doctor, Yaz, Ryan and Graham to a rural area in the Punjab on 17 August 1947, though Yaz had been expecting to be taken to Lahore in the 1950s from what her grandmother had told her of her youth. There they met Prem, who offered to take Yaz and the rest of Team TARDIS to Umbreen's house.

Upon arriving at Umbreen's house, Yaz claimed to be the sister of a third cousin of Umbreen's uncle Malik from fifteen valleys away. However, her confusion intensified when she learned that Umbreen was engaged to Prem, who looked nothing like her grandfather in the photos she had seen. Prem was also Hindu, whereas all of Yaz's family were Muslim. Realising she might not know her nani as well as she thought, Graham comforted her.

Yaz received henna art from her great-grandmother Hasna and spent the night before Umbreen's wedding with them and the Doctor. The following morning, she witnessed her grandmother marry Prem at the Pakistani border with India, tying their hands together as part of a Hindu wedding rite. Later, she witnessed how Prem gave Umbreen his watch, the face shattering when he dropped it as he passed it over.

When the Doctor realised that Manish was a murderer, Umbreen fled to Lahore. While she was taking her possessions, Yaz found a map with Sheffield marked on it, with Umbreen explaining how she wished to travel to the "exotic" city.

Back at the TARDIS, she and the Doctor spoke of Umbreen's life yet to come. She returned home to Umbreen in 2018 again. With henna still on her hands, Umbreen once again expressed distaste for her mother's designs. Yaz asked her if she was happy with her life and Yaz's grandfather; Umbreen said she was and expressed her love for Sheffield. Offering to tell Yaz the story of the watch, Yaz declined as she knew how much pain it had caused Umbreen. The two affirmed their love for each other once more. (TV: Demons of the Punjab)

Team TARDIS arrived on Kandoka's moon in +135 following the Doctor receiving a disturbing message in her Kerb!am delivery. Assuming positions as employees in the warehouse, Yaz was assigned to work in storage, where she quickly struck up a good working relationship with her new colleague Daniel Cooper. Yaz found Dan's Arcadium necklace after his death, and when she asked a TeamMate for help, she was surrounded by delivery bots and ran away.

When Yaz met with the rest of Team TARDIS at the Home Zone, she mentioned Dan's disappearance as one of the strange goings-on in Kerb!am. Subsequently, the Doctor, Ryan and Yaz left to confront Jarva Slade and Judy Maddox, and then discreetly investigated Slade's office and found his paper records, circumspect in the heavily-automated systems at Kerb!am.

Once the suspicious activity was attributed to the system, Ryan took Yaz and Charlie Duffy to save Kira Arlo from the TeamMates, riding the conveyor belts to reach the Foundation Levels of the warehouse. Yaz watched in horror as Kira was killed by exploding bubble wrap. She witnessed the resulting confrontation as Charlie was revealed as the saboteur that planted the deadly bubble wrap in packaging in protest of the low quotas on human labour in Kandokan law. In the TARDIS, Yaz requested taking Dan's necklace to his daughter and telling her how much her father loved her. (TV: Kerblam!)

Although the Doctor attempted to take Team TARDIS to see the coronation of Elizabeth I, Yaz and Graham noticed the location did not seem correct. In fact, they had landed in Bilehurst Cragg in the early 17th century, during the reign of James I. Yaz was shocked when shortly after she arrived, she witnessed a witch trial where Old Mother Twiston was drowned. Yaz was introduced to Becka Savage as a witchfinder alongside the rest of Team TARDIS. While travelling to Becka Savage's manor, she cast doubt on the superstitious traditions of the era.

Shortly after their arrival at the manor, the Doctor told Yaz to go to Willa Twiston and find out what she knew about the area. Coming across Willa's ritual in memory of her grandmother, Yaz saw a mud tendril coming from the ground and violently smashed it with a shovel before Willa ran away. Yaz informed the Doctor about her encounter with the tendril. Analysing the sample, the Doctor expressed confusion that the mud read as no different than usual on her sonic screwdriver. Yaz and the Doctor visited Willa's home, where they were served tea by Willa and comforted her due to the mistrust and suspicion of witchcraft that Willa experienced. Yaz, the Doctor, and Willa visited Mother Twiston's burial site once more and encountered the living mud tendrils yet again, as well as the corpse of Mother Twiston which was possessed by the Morax.

When the encounter ended, Yaz witnessed the Morax take Becka Savage's axe from the manor, before returning to Bilehurst Cragg in time for the Doctor's trial for witchcraft. After yelling at the townsfolk to let the Doctor go free, she witnessed the Doctor's escape from her chains, and Becka Savage being revealed as the cause of the Morax's presence in the village. When Yaz tried to defend King James from being kidnapped, she was knocked out by Morax energy. After defeating the Morax for good, Yaz departed Bilehurst Cragg with the rest of Team TARDIS. (TV: The Witchfinders)

Team TARDIS next arrived at a pizza parlour in New Port City, where they discovered the body of Iz. Yaz was crestfallen to see the Gornt's dead body, and used her police skills to investigate the pizza parlour and Iz's home. Yaz and Ryan discovered that Iz was a brilliant artist, and found teleportation coordinates to a party Iz had attended outside the Grey Zone. They teleported to the party's location, but were instead kidnapped by Ronan Sumners, who planned to harvest their sperantium to power the city's teleportation system. However, Yaz and Ryan were saved by Graham and the Doctor, and Sumners was accidentally ported into a Pizza-Porter oven. (PROSE: Gatecrashers)

After helping the Doctor halt a war on the planet Lobos between the dog-like loba and the human colonists, Team TARDIS had to return to retrieve Ryan's mobile phone. Accidentally, the TARDIS slipped almost six hundred years into the future, where the planet was now ruled by human zealots, served by slave loba. The zealots derived human superiority over loba from one joke by Graham, now worshipped as "the Good Doctor" while the real Doctor was forgotten. With women treated barely better than loba, Ryan and Yasmin were conflated into "St Rasmin". Almost immediately Yasmin was arrested for walking without a male relative. In prison, she met and befriended Pry, the leader of the resistance. This helped the Doctor learn both sides of the story. In the end, the Doctor succeeded in uncovering the lie of the zealots, setting the record straight and brokering a lasting peace between humans and loba. (PROSE: The Good Doctor)

Visiting 2018 Norway, the Doctor and friends discovered a strangely boarded-up and quiet cottage in the middle of nowhere. Exploring, they found a girl called Hanne hiding, terrified, as her father Erik had left her and she believed there was a monster in the nearby woods that took him. Yaz helped calm Hanne's nerves and explored outside with Ryan. Meanwhile, when an upstairs mirror began to distort, the Doctor determined that it was some form of dimensional portal. Promising to find Erik, Yaz entered the mirror alongside the Doctor and Graham.

They ended up in an anti-zone, an area made to protect space-time, and after being led through by Ribbons and avoiding the flesh moths inside, they discovered the other side: a mirrored world where Erik was safe alongside Hanne's mother, Trine, and Grace - both of whom had memories of dying and could not explain their presence. The Doctor explained to Yaz that they were in the Solitract plane, a conscious alternate universe that was exiled at the beginning of time as it was incompatible with the main universe and was now seeking friends, creating the figures of Grace and Trine as a result. With the reality falling apart, Yaz rejected the reality and was sent back into the anti-zone, managing to escape with the rest of the group. (TV: It Takes You Away)

In the TARDIS, the Doctor discovered nine separate distress signals all coming from the planet Ranskoor Av Kolos, which they followed to meet a man called Greston Paltraki, a commander who had visited the planet to stop a threat there. They eventually discovered that he was being threatened by Tzim-Sha, the Stenza they met on their first adventure, over the safety of some strange mineral-shaped objects. Yaz was tasked with accompanying Paltraki to find out his original mission purpose while the Doctor met with Tzim-Sha and after they were nearly attacked by SniperBots, they found more of the strange objects.

Yaz eventually discovered Andinio and Delph of the Ux, being forced by Tzim-Sha to use their powers with his technology to stasis freeze entire planets, starting with Earth, with the objects being previously attacked planets. Eventually saving the Ux, Yaz worked with the Doctor to connect the TARDIS to Delph, using his memory of the planets' original locations to teleport them back before they overwhelmed Ranskoor Av Kolos. It eventually worked, and with Graham and Ryan sealing Tzim-Sha in one of his own stasis pods, the Ux decided to see the universe with Paltraki and the Doctor's group headed on their way. (TV: The Battle of Ranskoor Av Kolos)

Sometime later, Yaz and her friends were treated by the Doctor to witnessing nineteen New Year's Eve celebrations in a row from across history. Before reaching the twentieth, however, the Doctor was alerted to some non-terrestrial things attempting to come together in Sheffield. Landing at an archaeological dig site on New Year's Day 2019, Yaz met Lin and Mitch who had uncovered an ancient burial site when a massive squid-like creature briefly appeared. Yaz led the two out of the area then, while trying to analyse the creature, Team TARDIS travelled to Graham's house, meeting Aaron, Ryan's father. As Ryan left to talk with him, Yaz returned to the TARDIS when the Doctor finally realised that the creature was, in fact, a Dalek.

Attempting to track the Dalek mutant, Yaz picked up Mitch and returned to Graham's house where Mitch taught them about the legend of the Three Custodians defeating a similar creature in the ninth century. Discovering that the Dalek was a reconnaissance scout that had taken control of Lin, Yaz joined the Doctor in tracking it down to a farm.

The Dalek eventually let go of Lin and Yaz helped take her back to the TARDIS. After the Dalek rebuilt a casing for itself before meeting the Doctor and taking off to summon a fleet to Earth, the group picked up Graham and Aaron and went to corner the Dalek. After they used a microwave owned by Aaron to melt its casing, the Dalek escaped and took control of Aaron, although the Doctor eventually managed to jettison it into a supernova and save Aaron's life, with Ryan finally forgiving him. Returning Aaron, Lin and Mitch to their lives, Yaz continued her adventures with the Doctor. (TV: Resolution)

Yaz and the rest of Team TARDIS accidentally landed in 1601 Bohemia where they met famous astronomers Tycho Brahe and a young Johannes Kepler and joined them on a gathering of scientists in a nearby castle laid out by Baroness Dagmar Ruskovitch. Yaz struck up a friendship with Johannes and stayed with him. However, when the Baroness took an interest in him, he was forced to leave and Yaz accompanied Graham and a furious Tycho through the castle. They eventually encountered Ruskovitch attempting to show him knowledge from the future, and when they were spotted, she transformed into a centaur to try and kill them. When Johannes stopped her, she ordered Yaz, Graham and Tycho to the dungeon, where Yaz scared the gatekeeper into letting them out by recording a video of him on her phone. Escaping, the three discovered how the assembled astronomers had been paralysed by the Baroness' orbs, so Yaz and Graham shattered them to stop the connection. With the Doctor and Ryan finally returning, she explained the situation before going to meet Ruskovitch again, where it was revealed that she and Dominik were actually trying to save the castle from the Catastrophia's Herald being summoned in the cellar. With the Doctor and Ruskovitch hunting the Herald and sealing it away, Yaz stayed behind, helping Ryan convince the assembled astronomers never to make the events known again. (COMIC: Herald of Madness)

When Yaz's "time of the month" came, the Doctor helped her feel better by relaxing in the TARDIS's Hungarian bathroom, giving her a hot water bottle and a bar of creamy, delicious chocolate, and telling her the story about how her eleventh incarnation met Amelia Earhart. (PROSE: Chasing the Dawn)

Later travels
While asking her superior officer for time off, Yaz was picked up by agents of MI6 and reunited with the TARDIS team. Working with Agent "O", the group infiltrated the operations of Daniel Barton, Yaz and Ryan posing as a reporting duo. During their investigation, Yaz was attacked by one of the Kasaavin, winding up trapped in their dimension, before she wound up in Australia with the Doctor, a trapped Kassavin having swapped places with her. After the group had confronted Barton at his birthday party and stolen his private jet, O revealed himself to be, another Time Lord and an old enemy of the Doctor's. After summoning two Kasaavin to take the Doctor away, the Master teleported away and left the humans to die. Before the plane crashed however, a recording of the Doctor appeared and told them how to get to safety. Back on the ground, the trio found that they were marked as persons of interests by Barton's influence and were forced to go on the run. The trio eventually tracked Barton down to a warehouse where they learnt his scheme was to turn humanity into hard drives. As the Master arrived to gloat, the Doctor revealed that, through the Master's TARDIS, she had sabotaged the plan, leaving the Master to be taken prisoner by the Kasaavin. Back aboard the TARDIS, the companions requested that the Doctor say who she really was with her giving them the barest of details on her past. (TV: Spyfall)

The Doctor soon promised to take her friends to Woodstock, but they wound up in London in 1969 instead. Recognising the date, the Doctor explained how, back in 2007, she and her friend Martha Jones had been displaced to this time and place by a Weeping Angel. Unsure as to why they'd been brought here, the Doctor sent her companions to watch her past self, the Tenth Doctor. Following him around all day, the companions found nothing suspicious. Though the Doctor intended to leave soon afterwards, Yaz convinced her to stay a while longer, noting the similarity to police investigations. As they followed the Tenth Doctor again, Yaz realised that he was tracking the temporal emissions of their TARDIS. To prevent this, Yaz approached him and claimed to work for the Time Agency only for her bluff to quickly be called. When Ryan and Graham approached, the Doctor advised all three to turn around and not blink as a Weeping Angel had just approached.

Through all three companions keeping an eye on the Angel, the Tenth Doctor was able to reach the TARDIS and carry them to safety, meeting up with the Thirteenth Doctor and Martha Jones who had discovered a nest of Autons. When the TARDIS next landed, the Angels attacked to try and feed off it only for the Doctors to dematerialise in such a way that forced the Angels to observe each other. Travelling to the lair of the Nestene Consciousness, the Doctors lured the Angels in, who sent the plastic back in time, before trapping the Angels using a stellar net and depositing them in a sun. After saying goodbye to Martha and the Tenth Doctor, the companions requested to be returned home for some time off. (COMIC: A Little Help from My Friends)

After an incident with a squid, Team TARDIS was unexpectedly teleported to Tranquility Spa. Though intending to relax, a hole in the resort's ionic membrane let in the native lifeforms, beasts known as the Dregs. After the creatures had abducted Benni, an ultimately futile rescue mission was mounted where it was found that the planet, Orphan 55, was actually a future version of Earth, destroyed by a nuclear war. Back in the TARDIS, the Doctor assured her companions that Orphan 55 was but a possible future for Earth and could be altered if the right choices were made in 2020. (TV: Orphan 55)

Tracking alien technology in the 20th century, the group ran across Nikola Tesla who had found a Thassorian orb. Left with Tesla at his lab, Yaz was abducted by the Skithra who used her to force Tesla into repairing their damaged craft before the Doctor rescued them. The Skithra later made another attempt to invade Tesla's Wardenclyffe laboratory only to be forced away when the tower conducted a lighting strike and sent their ship warping away. As the group left the 20th century, Yaz expressed dismay that Tesla would never be regarded as a genius in his own time but the Doctor assured her that the man's legacy would live on forever. (TV: Nikola Tesla's Night of Terror)

After roughly twenty minutes of watching the Doctor fiddle with the TARDIS, looking for traces as to the Master's location, the group travelled to contemporary Earth to deal with a Judoon invasion of Gloucester. After speaking with the barista Allan, the group was led to believe that the Judoon were hunting Lee Clayton. Making their way to his flat, though losing Graham in the process, the Doctor bluffed that she was an Imperial Regulator and that Yaz was a local law liaison. Invoking the fictitious Article 12 to grant themselves an audience with Lee, the trio were invited inside the flat where the man agreed to meet the Judoon if his wife Ruth was taken to safety. As the Doctor took the woman away, Yaz and Ryan went outside to speak to the Judoon only to be teleported away by Captain Jack Harkness. Having been previously been told by Graham that the Doctor was now a woman, Jack had assumed Yaz to be the Doctor only for Graham to inform him that there were now three companions aboard the TARDIS. After being told that the Judoon were the reason for his malfunctioning scoop, Jack was forced to take his leave when the stolen ship's security nanogenes began attacking him. Teleporting the trio back to Gloucester, he warned them of the "Lone Cyberman" and to make sure that it didn't get what it wanted to rebuild the Cyber-Empire. When the trio reunited with the Doctor, they passed on Jack's message before she revealed that the fugitive was an incarnation of herself, one she could not remember being, and feared that time was rewriting around her. (TV: Fugitive of the Judoon)

The Doctor gave Yaz an in-depth tour of her TARDIS, during which she briefly told her about "Ruth's TARDIS". (PROSE: TARDIS Tour)

During the Praxeus infection on Earth, she was instrumental in stopping the virus. (TV: Praxeus)

While she was on a break from travelling, she had strange dreams relating to her encounter with Anita Patel three years beforehand. After helping the Doctor find and defeat Zellin, who was the cause of the nightmares, she met with Anita once again and gave her the 50p she owed her. (TV: Can You Hear Me?)

Fighting the Cybermen
While dealing with strange events in Villa Diodati, concerning Mary Shelley, the TARDIS team finally encountered the Lone Cyberman. Despite Yaz's and the other members of the team's warnings, the Doctor gave up the Cyberium to save Percy Shelley. (TV: The Haunting of Villa Diodati)

Travelling to the far future to stop the Lone Cyberman, Team TARDIS helped the last humans escape the last of the Cybermen. However, Yaz, along with Graham, got separated from Ryan and the Doctor and ended up on a Cybercarrier carrying an army of Cyber-Warriors. As the humans took control of the ship, the Cybermen boarded and reactivated the Warriors, storming the bridge. (TV: Ascension of the Cybermen)

At Graham's suggestion, the group donned the cyber-suits of inactive Cybermen to hide idside. They later reunited with Ryan, Ethan, and Ko Sharmus. Together with Ravio and Yedlarmi, the group entered the Boundary and found themselves on Gallifrey. There, they met up with the Doctor, who sent them away via another TARDIS to sacrifice herself to stop the Master with the death particle. Materialising back on 21st century Earth, Yaz mournfully questioned what had happened to the Doctor, presuming her dead, unaware that Ko Sharmus had taken the Doctor's place. (TV: The Timeless Children)

Personality
Yasmin was ambitious. Although outwardly confident, she wasn't overly so, and was aware that she still had much to learn; she viewed "every day [as] a learning day". (TV: The Woman Who Fell to Earth) She held high aspirations, telling Rosa Parks that she wanted to be at the top of the police force. Despite enduring racism in American 1955, she spoke positively, thanking Rosa Parks for making it possible for her to be a police officer, and that (despite the hard times) America would eventually have a black President. She had a sense of humour and joked about her supposed Mexican blood when she was misidentified in Montgomery. (TV: Rosa) She rarely brought friends home and her family considered her to be "married to her job". (TV: Arachnids in the UK)

Yasmin was naturally curious, never failing to leap through into the unknown. (TV: Praxeus, The Timeless Children) She considered traveling with the Doctor everything she had ever wanted. (PROSE: Can You Hear Me?)

Yasmin was known for her strong will. Despite numerous racial slurs hurled at her during the course of her life, Yaz refused to let it get her down. Instead she worked hard to be the better person. (PROSE: The Good Doctor, TV: Rosa, The Witchfinders) Though she was bitter at the memory of such things costing her friends. (PROSE: The Good Doctor) According to fellow companion Graham O'Brien, nothing deterred Yasmin; she was always fighting, never afraid and never beaten. (TV: The Timeless Children)

Yaz had a dislike of "being on duty at the city centre on a Friday night". (WC: Case File Two)

She was not arachnophobic. (WC: Case File Four)

Skills
Her police experience meant that she was a good negotiator, capable of forming a truce between two opposing civilians. (TV: The Woman Who Fell to Earth) Her family liaison training helped her to provide support to those recently bereaved. (TV: The Witchfinders) She was also skilled in helping calm people by reassuring them of something they believed in already. (TV: It Takes You Away)

She had a good knowledge of history, recounting the significance of Rosa Parks's refusal to give up her bus seat to a white passenger. She knew what time of day Parks was arrested and had some idea about her profession. This knowledge would help the Doctor keep history in order when Krasko's actions put the past in jeopardy. (TV: Rosa) Yaz was quite good at keeping herself from making verbal slip-ups when visiting the past, especially if it would affect her future. (TV: Demons of the Punjab)

Yasmin had a lovely singing voice. (PROSE: The Good Doctor)

Behind the scenes

 * Yaz is the first televised companion of South Asian descent.

Yasmin Khan