Nardole

Nardole was a companion of the Twelfth Doctor.

Escaping a former life of crime which eventually made him an employee of River Song, Nardole expressed deep remorse for his actions and so attempted to make up for his illicit past.

While working for Dr Song on Mendorax Dellora, he was beheaded by the body of King Hydroflax, who used him to obtain information on her whereabouts. Knowing River would go to her death in the Library following their twenty-four years together on Darillium, the Doctor reassembled Nardole out of fear of being alone.

River's final instruction for Nardole was to save the Doctor from executing. He did so, but not before the Doctor swore an oath to protect her body for a thousand years. Missy was placed in a Quantum Fold Chamber and Nardole kept the Doctor to his word.

As the Doctor took on Bill as his companion, Nardole eventually joined them on their travels after many protests that the Doctor was ignoring his oath. Following a battle with the Cybermen onboard a colony ship, Nardole left the Doctor's company on his instructions to defend a small group of villagers.

Former life of crime
Nardole stated that he didn’t know his true origins, as he was "found". (TV: The Doctor Falls) On one occasion, he jokingly claimed to have Scottish heritage, descending from the clan "MacNardole". (PROSE: Plague City)

Nardole formerly worked as a con artist and black market trader. He would later express remorse for this period of his life. (TV: The Doctor Falls)

Nardole had an ex called Velma, who worked as an actress. She left him for an AI at a call centre. (TV: Oxygen) He also once had an imaginary friend, until he left him for someone else. (TV: The Lie of the Land)

Nardole once swapped his face while "on the run". (TV: Oxygen) He was blue at one point, (TV: World Enough and Time) and had friends who were "bluish". (TV: Oxygen) However, he was never green. (COMIC: A Confusion of Angels) At some point in time, Nardole also replaced his left hand with one he won in a game of some sort. (TV: The Lie of the Land)

Nardole studied the Tarovian martial arts for "a while" and reached the rank of Brown Tabard. He also learned the Tarovian neck pinch. However, he could only perform it with his original right hand and not with his replaced left hand. (TV: The Lie of the Land)

Working for River Song
Nardole first encountered the Doctor while working for River Song on Mendorax Dellora in 5343. He was told to find the surgeon. The surgeon was required as River Song needed to extract the Halassi Androvar from the head of King Hydroflax. However, Nardole accidentally found the Twelfth Doctor and brought him to Professor Song instead.

When River and the Doctor eventually escaped Hydroflax's ship with his head in a bag, Hydroflax's mechanical body turned to Nardole and wanted to extract strategic information. Although Nardole claimed to know very little of River's plans, there was only one way for Hydroflax's body to be sure, so it removed Nardole's head and attached it to its own. Later, whilst holding a gun to Nardole's head, Hydroflax's body forced him to draw in Ramone, whose head the body took while storing Nardole's within itself.

On the Harmony and Redemption, the body pulled Nardole's head out of storage to confirm River's identity before putting it back against his protests.

After the crash of the Harmony and Redemption on Darillium, Hydroflax's body was recovered from the wreckage. As the hostile onboard computer had been destroyed by the Doctor, Nardole and Ramone shared control of the body, working in a restaurant situated before the Singing Towers. When River arrived several years after the crash, Ramone was in control as Nardole was getting some "me time" inside the body, something he admitted was hard when he greeted River from inside Hydroflax's body. (TV: The Husbands of River Song)

24 years on Darillium
The Doctor and River Song spent their final 24 years together on Darillium. During this time, the Doctor grew fearful of being alone, and so "cut [Nardole] out of Hydroflax" and "glued" his head onto a new body (TV: The Return of Doctor Mysterio, The Pyramid at the End of the World) rendering Nardole partly cybernetic, (TV: The Pilot) and giving him a "cheap" pair of human lungs. (TV: The Pyramid at the End of the World)

At River Song's final request, Nardole followed the Doctor to a planet where was to be executed. Here, the Doctor swore an oath to protect her body for a thousand years. Disguised as a priest, Nardole intervened in the proceedings and instructed him not to kill Missy as his late wife wouldn't approve. The Doctor let Missy live, and he and Nardole locked her in a Quantum Fold Chamber. At the Doctor's oath, the pair would guard the vault for the next thousand years. (TV: Extremis)

Guarding the Quantum Fold Chamber
Nardole became the Doctor's companion, and saw it as his duty to ensure the Doctor was all right following River's death. (TV: The Return of Doctor Mysterio)

The Doctor and Nardole settled at St Luke's University in Bristol, where they spent nearly seventy years watching over the vault which was now hidden beneath the campus. While stuck on Earth, the Doctor took a job as a lecturer and Nardole acted as his valet. (TV: The Pilot)

While guarding the vault, (TV: Extremis) the pair still found time for an Earth-based adventure. Together they investigated Harmony Shoal with the help of "the Ghost". He also spent some time in Constantinople, where he ruled "firmly, but wisely". (TV: The Return of Doctor Mysterio)

It was at St Luke's University where the Doctor and Nardole first met canteen worker Bill Potts and encountered a sentient oil puddle. Realising it was after them and not the vault, the Doctor, Bill and Nardole tried to evade the creature, but it followed them through time and space. They travelled to a war zone in the Dalek-Movellan War, where Nardole ran interference and sealed off the area of all but one of the Daleks. The last Dalek was actually the oil creature, which had taken over the body of Heather, and remembered Heather's promise to never leave Bill. Bill released "Heather" of her promise, and the trio returned to St Luke's. (TV: The Pilot)

When the Doctor formally invited Bill to join him as his companion, he sent Nardole to put the kettle on in the Doctor's office whilst he secretly introduced her to all of time and space. (TV: Smile) Bringing tea with a "bit of coffee" in it to "give it some flavour", Nardole was dismayed to learn that the Doctor and Bill had been to Regency London while he was out, which he considered "naughty" of the Doctor as he had broken his oath, only for the Doctor to argue that his return proved he kept it. After being told by the Doctor to "leave [him] alone", a frustrated Nardole voiced his frustrations to himself while standing guard outside the chamber, before being interrupted as Missy started heavily knocking on the door. Though acknowledging that the Doctor had been "distracted" by Bill, Nardole, hiding his fear, asserted to Missy that he would still stand guard and would not let her escape. (TV: Thin Ice)

After the Doctor had saved Bill and her friends from a creaking house and a creepy Landlord, the Doctor gave Nardole the night off, much to his annoyance. He was disappointed when he learned that the Doctor had put a piano in the Vault, saying that he "never learns". (TV: Knock Knock)

After introducing Bill to space-time travel, the Doctor often left Nardole on Earth whilst the two had adventures. (PROSE: The Shining Man, Diamond Dogs)

Travels with the Doctor and Bill
Going to desperate measures to ensure that the Doctor kept his oath and remained on Earth guarding the vault, Nardole removed fluid link K57 from the TARDIS after having been informed by the Doctor that the TARDIS couldn't travel without it. The Doctor revealed to both Nardole and Bill that he'd lied and took them on an adventure to Chasm Forge, a space station from which the TARDIS had detected a distress signal.

On the space station, the trio was met with dangerous consequences where oxygen was lacking and needed paying for and the crew's spacesuits wanted to kill them. Finally, the three returned to Earth and Nardole revealed his relief that the Doctor hadn't been injured or killed on the adventure as the person within the vault would be able to sense his weakness. However, the Doctor revealed that he'd been blinded by being exposed to the vacuum of space for too long. (TV: Oxygen)

Soon after being informed by the Doctor about an alien race who had been using a simulator of Earth and all its inhabitants as means to discover the planet's weaknesses, Nardole accompanied his friends to Turmezistan where a 5,000-year-old pyramid stood which hadn't been there the day before.

It was not long before it was revealed that the Monks were behind the pyramid's erection and, after displaying their powerful abilities of teleportation and telekinesis, the Monks revealed that they wished to rule the Earth but would only do so when they were asked as ruling the population would be easier if they went along with the Monks' plan.

The group learned that in a year, the world would be dead and Nardole aided the Doctor in attempting to figure out why this would happen and how to prevent it. By shutting down the CCTV cameras in the labs on the UNIT watchlist, Nardole was able to help figuring out which lab was the right one. When they got to Agrofuel Research Operations, the Doctor ordered Nardole to take the TARDIS to the other end of the lab shortly in the future as Nardole was "human enough" to be affected by the bacteria as the Doctor got Nardole's "lungs cheap". Nardole moved the TARDIS but collapsed from the effects of the bacteria. As the Doctor called to Nardole for help, he lied on the TARDIS floor, unmoving. (TV: The Pyramid at the End of the World) After being laid up for six weeks from the effects of the bacteria, Nardole recovered thanks to his alien physiology. (TV: The Lie of the Land)

After recovering, Nardole searched for and eventually located the Doctor on a prison ship. Nardole and the Doctor concocted a plan to test if Bill was still herself by setting up a scenario where the Doctor pretended to have converted to the Monks side.

Six months after the invasion began, Nardole visited Bill at her home and proved he was himself by answering questions about their adventures together. Nardole presented Bill with the location of the Doctor, claiming to have recently found him. Nardole got the two onto the prison ship where he watched the confrontation between Bill and the Doctor. After the Doctor faked a regeneration, Nardole laughed along with everyone else when the Doctor revealed the truth. After the Doctor told Nardole they needed Missy's help, Nardole was shocked that they had gotten to that point.

Nardole remained behind on the ship with the Doctor's soldiers when he and Bill went to talk to Missy. Upon their return, Bill admitted that Missy had stated that the best way to end the invasion was to fry Bill's mind. Refusing to consider the idea, the Doctor led Bill, Nardole and his soldiers to the Cathedral to destroy the device the Monks were using to broadcast their altered version of history. When one of the soldiers fell back under the Monks influence, Nardole rendered him unconscious with a Tarovian neck pinch. Nardole then watched the Doctor's attempt to overwhelm the machine with the true version of history and refused to stop Bill's attempt to sacrifice herself to stop the Monks, respecting her decision. After Bill broke the link, Nardole questioned what the Monks would do next and was informed that they would run. He watched with Bill and the Doctor as the Monks retreated from the Earth. (TV: The Lie of the Land)

When the Doctor was "correcting" the books of the Terrance Dicks Library, the building was demolished by a bowship piloted by the Doctor's daughter, Jenny. After Jenny had explained the events that led to her arrival, "possessed" UNIT forces arrived and starting advancing menacingly. When the Doctor ushered everyone into the TARDIS, it was found to have been merged with that of his tenth incarnation, with the Eighth and Ninth Doctors soon arriving. The Doctors managed to trace and neutralise the malignant energy but doing so left only the Twelfth Doctor with any memories of what had happened, him happily taking Bill and Nardole away to tell them what had just happened. (COMIC: The Lost Dimension)

The Doctor, Bill, and himself once visited Edinburgh in 1645, where they encountered a city plagued by Ghosts and the Plague. (PROSE: Plague City)

Whilst visiting Mars, the Doctor sent Nardole to fetch some rope from the TARDIS so they could reach Bill, who had fallen down a hole. Once inside the TARDIS, she mysteriously took Nardole back to St Luke's. Unable to make the TARDIS cooperate, Nardole went to the Vault and let Missy out to help him reach Mars. She and Nardole arrived on Mars after the Doctor and Bill resolved a conflict involving Ice Warriors and humans. (TV: Empress of Mars)

When the Vault needed a new Relative Dimensional Stabiliser, the Doctor took Bill and Nardole to Übermarket where Bill helped a lost Pathicol child called Tyto find her parents. (COMIC: The Great Shopping Bill)

When the trio answered the distress signal of the Jeden, they discovered the Weeping Angels were using the Heavenly Hosts as breeding stock. When one had sent the Doctor a century into Sto's past, Nardole hoped to use the TARDIS to rescue him only to be informed that Missy had taken control of it. After Bill proposed venting the Angels into space, Nardole worked with Margaret Ag-Kris Therur-Ford Jingatheen before the Doctor returned, sending the Jeden into a nearby red giant after the refugees aboard had been evacuated. (COMIC: A Confusion of Angels)

Nardole was with the Doctor and Bill when they were trying to settle a bet on what happened to the Ninth Legion of the Roman Army. When they arrived in 2nd century Scotland, he expressed annoyance at the Doctor abandoning his oath again, but he followed the Doctor to investigate. The pair were captured by Picts and soon found out a light eating locust had been released from a cairn leading to another dimension so it could fight off the Roman army. They escaped after the Doctor distracted the Picts with popcorn.

When the Doctor entered the cairn, Nardole stayed outside and re-encountered the Picts. Two days passed for him whilst the Doctor went in for a few seconds. In those two days, Nardole had his face painted to resemble the Picts and told stories outside the cairn. After the Doctor emerged, they began working on a plan to defeat the creature. The pair were reunited with Bill when she arrived with the last survivors of the Ninth Legion escaping the creature. The trio then made the two sides work together to save the world, which the Doctor did by using a device which turned light into poison to force the creature back into its dimension. Nardole escaped with the Doctor, Bill and the remaining Picts after the Romans and Kar chose to enter the portal to fight the remaining creatures.

Upon returning to the TARDIS, Nardole was angered by the presence of Missy in the TARDIS. The Doctor explained that she was doing "maintenance work" for the TARDIS and that she was trapped inside, however, Nardole wasn't convinced (TV: The Eaters of Light)

Nardole, along with Bill, became temporary companions of Missy when the Doctor decided to give her a "test run" to test her loyalties. They arrived on a Mondasian colony ship flying towards a black hole and encountered Jorj, who shot Bill out of fear. Nardole, the Doctor and Missy remained at the top of the ship to incapacitate Jorj and eventually made their way down to rescue Bill, only for ten years to have passed for Bill, who had been converted to a Mondasian Cyberman by. The Doctor and Nardole encountered both incarnations of the Master as they discovered Bill. (TV: World Enough and Time)

Nardole escaped from the two Masters whilst they captured the Doctor. He found a spaceship and used it to fly the Doctor, Bill and the Masters to safety when the Cybermen began to attack them. When they arrived on Floor 0507, Nardole took command of the villager's defence due to the Doctor being unconscious, and he was able to turn the floor of the spaceship into a minefield to stop the Cybermen progressing. During this time, Hazran began to take a liking to him. When the Cyberman began to outnumber them, the Doctor told Nardole to take the remaining children and adults to a higher floor and stay there to protect them. Nardole initially opposed this but eventually relented, seeing his role as a babysitter a fitting way to make up for his past.

As the Doctor used Nardole's program to battle the Cybermen, Nardole led the villagers to safety on Floor 0502. Sometime later, one of the children approached Nardole and suggested that his friends could still return. Appearing to accept that Bill and the Doctor were most likely dead, Nardole refuted the statement. Nardole stated that the Doctor had destroyed most of the Cybermen, meaning that they would need time to regroup and come after the villagers again. Nardole left with the children, stating that he'd "think of something" before the Cybermen returned with the children teasing Nardole about Hazran's interest in him. (TV: The Doctor Falls)

Whilst defending the people aboard the colony ship, Nardole kept in regular contact with Bill, who had returned to Earth to continue studying at St Luke's University. He remarked how he had broken his legs whilst traversing the banana meadow, but liked it because the children could now push him around in a comfy wheelbarrow. (WC: The Best of Days)

Nardole spent the rest of his life on the colony and, in the words of his glass avatar, lived "happily ever after" despite "a couple" of reprisals from the Cybermen. Nardole ultimately died at the age of 728, having had "good times" with six wives, two of whom he was married to at the same time. Though Cybermats continued to show up every spring to the end of his life, the colonists had "sorted" their conflict with the Cybermen. (PROSE: Twice Upon a Time)

Legacy
The Twelfth Doctor remembered Nardole, along with his other past companions, as he lay dying on the TARDIS floor. (TV: The Doctor Falls)

Following his eventual death, Nardole's memories were retained by the Testimony, who recreated him as a glass avatar along with his six wives. As Nardole recalled, he got taken in "by accident", as the Testimony mistook him for a human. When Nardole told them to be "heartless and cruel" and send him back, they "gave in" and allowed him to remain. (PROSE: Twice Upon a Time) The Testimony sent the avatar of Nardole alongside Bill Potts to visit the Doctor before his regeneration into the Thirteenth Doctor. The Twelfth Doctor thanked both his friends for what they had done for him and they shared a cuddle before Nardole and Bill's avatars teleported away. (TV: Twice Upon a Time)

Personality
Nardole was loyal and humble. He saw it as his duty to make sure the Doctor was alright following the death of River Song. (TV: The Return of Doctor Mysterio) However, Nardole was far from submissive. He took his position with a firm attitude, strongly insisting the Doctor stay true to his oath that prevented him from going off-world outside of emergencies. The Doctor even referred to Nardole as his "mum" because of this. (TV: Smile) Bill even saw him as "a sort of bodyguard" for the Doctor. (PROSE: Plague City) Nevertheless, he was also rather timid and could show great fear when faced with danger. He was particularly scared of heights. (TV: The Husbands of River Song)

Due to the lengthy time they spent together on Darillium, and later at St Luke's University, Nardole knew a great deal about the Doctor, such as the Time Lords non-interference policy. (TV: The Return of Doctor Mysterio) He also pointed out to Bill that the Doctor "never notices the tears" after spotting her upset about losing Heather, (TV: The Pilot) knew he could be "so cocky" (TV: Oxygen) and scolded him for trying to avoid personal problems. (TV: The Return of Doctor Mysterio)

He was easily deceived. He mistook the Doctor for "the best surgeon in the galaxy", (TV: The Husbands of River Song) but although he could sometimes appear incompetent, he didn't fall for the Doctor's plan to get rid of him by asking him to get a packet of crisps from Birmingham. (TV: Oxygen) he was also knowledgeable and, despite not originating from Earth, knew that New York wasn't a capital city, unlike Washington DC. (TV: The Return of Doctor Mysterio)

Nardole could also be child-like. He happily played with children's toys, referred to the toilet as "the little boy's room", (TV: The Return of Doctor Mysterio) described the Doctor's off-world adventuring as "naughty", (TV: Thin Ice) and enjoyed a "cuddle" with the Doctor and Bill. (TV: Oxygen)

Nardole had a distaste for humans. He refused to make Bill tea because he's "not a slave for any human, that's for sure". (TV: Smile) He later referred to them as "smelly humans" and appeared to think of them as lesser lifeforms, even suggesting to the Doctor "you go upstairs and farm the humans". (TV: The Doctor Falls) However, he grew fond of Bill over time and excitedly greeted her after not seeing her for six months. At this time, he also called himself by the nickname of "Nardie". (TV: The Lie of the Land)

Nardole had a criminal past. He referred to a time when he was "on the run", and was quick to deny that he was capable of both murdering and robbing the workers aboard Chasm Forge. (TV: Oxygen) In addition to this, Nardole claimed it was unreliable to leave a bunch of humans in his care, remarking "You know what I was like. There's more than three people in a room, I'll start a black market. Send me with them, I'll be selling their own spaceship back to them once a week." (TV: The Doctor Falls)

According to Nardole, he relied on "air, water, food and beer" to survive. (TV: The Pyramid at the End of the World)

Nardole also thought of himself as very good-looking, (TV: The Pyramid at the End of the World) even understanding Hazran's crush on him as her being only human. (TV: The Doctor Falls)

Skills and abilities
Nardole was capable of flying the TARDIS, a talent displayed by very few of the Doctor's previous travelling companions, (TV: The Return of Doctor Mysterio, The Lie of the Land) although he was unable to make it return to Mars without Missy's assistance. (TV: Empress of Mars)

He was also adept at using a sonic screwdriver. When they travelled to a Dalek-Movellan war zone, he used it to short-circuit several panels and successfully quarantined all the Daleks in the vicinity to prevent them from attacking the Twelfth Doctor and Bill. (TV: The Pilot)

Following his reassembly at least, Nardole had a longer-than-human lifespan. He remained at St Luke's University for at least a number of decades, during which he didn't appear to age. (TV: The Pilot) The sonic sunglasses registered his age as 237 during the Monks' invasion of Earth. (TV: The Pyramid at the End of the World) He ultimately died at the age of 728. (PROSE: Twice Upon a Time)

While still vulnerable to contamination from deadly Earth bacteria due to being "human enough", Nardole was capable of surviving where humans wouldn't due to his alien physiology. However, this could make him too ill to do anything for up to six weeks. (TV: The Pyramid at the End of the World, The Lie of the Land) He would also die without an oxygen supply, much like an organic being. (TV: Empress of Mars)

At 30.3 degrees Celsius, Nardole had a lower body temperature than the average human. This was likely due to his cybernetic body. (TV: The Pyramid at the End of the World) His left hand was not his original hand but rather one he won in some kind of game. (TV: The Lie of the Land)

Nardole was a skilled computer expert and hacker, being able to hack Harmony Shoal's computer system. (TV: The Return of Doctor Mysterio) He could also hack the cameras of every lab in the UK to figure out which one the Monks were monitoring. (TV: The Pyramid at the End of the World) During the siege of the Cybermen against the inhabitants of Floor 0507 of a Mondasian colony ship, Nardole used a computer to locate the fuel lines on the floor and subsequently ignite them in conjunction with the villagers firing their rifles at the Cybermen, creating the illusion their weaponry was vastly superior as it helped defeat many Cybermen. He also implied he could take control of the whole ship if he desired, but wouldn't as he had changed due to having met the Doctor. He could also fly a shuttlecraft. (TV: The Doctor Falls)

For a time, Nardole studied the Tarovian martial arts and gained the rank of Brown Tabard. He could do the Tarovian neck pinch, which rendered a victim unconscious in seconds. However, he could only do it with his right hand. (TV: The Lie of the Land)

Appearance
Nardole resembled a short, hairless, humanoid male in his early 40s with a rotund build. (TV: The Husbands of River Song) Missy once described him as "that bald bloke who looks like an egg". (TV: The Lie of the Land) According to his glass avatar, his hair was invisible and his nipples were made of glass. (TV: Twice Upon a Time) He claimed that he hadn't seen his true face in years and that he swapped it out for his current face when on the run. (TV: Oxygen) He also mentioned that he was once blue-skinned. (TV: World Enough and Time)

His height was once given as 167.7 cm, roughly 5.5 feet tall. He weighed 216.1 pounds, and had a resting temperature far below human average- 30.3 degrees Celsius, or 86.5 degrees Fahrenheit. This further suggested his cyborg nature, along with a comment about his lungs having been bought "cheap" - this, in fact, made him "human enough" to be harmed by a deadly bacteria. (TV: The Pyramid at the End of the World) Additionally, when he showed Bill the Doctor's office, his arm made a mechanical sound, and a bolt fell from it. (TV: The Pilot)

Clothing
When he first met the Doctor on Mendorax Dellora, Nardole wore a crimson duffle coat matched with a multi-coloured beanie to cope with the snowy climate. (TV: The Husbands of River Song) He continued to wear the same coat when travelling with the Doctor, (TV: The Return of Doctor Mysterio, The Pilot, Oxygen, The Pyramid at the End of the World) but also wore a plaid red vest with square glasses when assisting him at St Luke's University, (TV: The Pilot, Smile, Thin Ice, Oxygen) or a plaid jacket. (TV: Knock Knock, Extremis, World Enough and Time, The Doctor Falls) Completing his outfit was a pair of rust-orange slacks, a pair of brown leather shoes, and a simple button up shirt. (TV: The Return of Doctor Mysterio)

Nardole often dressed in attire appropriate for the locations or periods in which he found himself. After Nardole ruled 12th century Constantinople, he was seen wearing imperial garb. (TV: The Return of Doctor Mysterio) When visiting Edinburgh in 1645, he wore a Tam O'Shanter, kilt and Sporran. (PROSE: Plague City) Similarly, while visiting 2nd century Aberdeen, Nardole changed into a Pictish outfit, complete with face paint; previously, he'd been wearing his pajamas, robe, and slippers. (TV: The Eaters of Light)

Doctor Who The Official Annual 2018
According the Doctor Who The Official Annual 2018, which is not accepted as a valid source for in-universe articles on this wiki, Nardole was from Mendorax Dellora. While he did not initially like humans, Nardole came to enjoy tea and knitting, even knitting his own hats. He had a Brown Tabard in Tarovian martial arts.

Other matters

 * Several characters in Doctor Who: Legacy are based on Nardole, including Hydroflax with Nardole's head, which is used as both an ally and an enemy.
 * Nardole is mentioned by the Twelfth Doctor in Doctor Who and the micro:bit.
 * Aside from the Doctor, Nardole is only the second character to appear in three consecutive Christmas specials. He appeared in all the Christmas specials from 2015 until 2017. Previously Clara Oswald had done the same between 2012 and 2014.
 * While it's never confirmed, it's implied Nardole lives in the TARDIS during his time with the Doctor, as he emerges in his pajamas during their adventure in TV: The Eaters of Light.
 * Nardole is the first televised non-human companion of the Doctor since Handles in TV: The Time of the Doctor, and the first full-time non-human companion of the revived series.
 * Nardole is the only regular companion introduced under Steven Moffat to have never died on screen.