Giles

Giles was a technology expert at P.R.o.B.e., joining at some point before 2014. He was second-in-command of the organisation, being told that he would become the boss if anything happened to Liz Shaw. After Liz decided to retire to marry Patsy, (HOMEVID: When to Die) Giles took over as Director. (WC: Shadows of Doubt, HOMEVID: Goo!, etc.à)

Giles seemed to keep his full name a secret. He signed his name "Giles x" on P.R.O.B.E. documentation (HOMEVID: Goo!) but introduced himself in his video diaries as "P.R.O.B.E. Director Giles" (WC: Case File - Doctor X, etc.)

As P.R.O.B.E. technician
In 2009 Giles visited Brittany Mordley in Philadelphia with Patricia Haggard and her partner. They accompanied her to Wawa's, but Giles had left his wallet in the hotel so couldn't buy anything. (PROSE: Silver-Tongued Liars)

In 2011 Giles and Archie MacTavish travelled to The Vault to investigate the coverup of some deaths. They found out that Cyberon was behind the deaths, and Giles managed to negotiate the Cyberon into retreating after it struggled to convert the DNA of a young girl, Abigail, and instead caused itself to become infected with lycanthropy. (PROSE: A Worthy Successor)

At some point, he and Archie fought Shed Scales. (PROSE: The Door We Forgot)

In 2014, Giles found Box in P.R.o.B.e.'s storage hold and managed to repair her. He disapproved of Liz when she took on the Paul Reynish job due to the substantial workload they already had. Although he wanted to go with her on her mission, Liz told him to stay to lead P.R.o.B.e. if she did not return. (HOMEVID: When to Die)

The new Director
Giles was made Director of P.R.o.B.e. by Haggard (WC: Shadows of Doubt) after he was interviewed by the former director. During the interview Giles recounted the tale of how he negotiated the withdrawal of the Cyberon in the Vault three years prior. (PROSE: A Worthy Successor)

Giles was on holiday when he was asked to investigate a spaceship crash nearby. Giles met Maxiassa, the pilot of the spaceship. An alien called Mar'tuth appeared and began to hunt Maxie. Giles and Maxiassa killed Mar'tuth by using mirrors to deflect its glitches back onto itself. Two months later, with the help of Sir Andrew Williams, he found Maxiassa asylum on Earth, and gave her his old job as technician at P.R.o.B.e. (PROSE: She Came From Another World!)

On 23 April 2018 Archie and Giles investigated at Poltergeist at Garry Nelson's house. (WC: Case File - Peckham Poltergeist)

Later, Archie would die in a Manchester ritual. (PROSE: The Door We Forgot) Before Giles returned from Manchester he sought out every medium and witch doctor in the city to bring him back but it didn't work. On 7 November 2018 he recorded a case file to talk about Archie's death. (WC: Case File - Manchester)

Giles and the team
Giles eventually had a team that consisted of Agamya, Bedevere, Maxie Masters, and Tasha Williams. (PROSE: The Door We Forgot)

Giles and P.R.o.B.e. had to prepare for perihelion. (WC: Shadows of Doubt)

On 5 February, 2019, Giles met Stacey Facade under the London Eye, and Giles fell deeply in love with Stacy. A week later, he recorded a video diary entry, where he spike about how he loved Stacy and how he suspected his team of being jealous. Later, he and Stacy ate dinner in the Royal Observatory.

A day later, he recorded another video diary where he handed in his notice, and planned to "start a new life" with Stacy somewhere remote like New Zealand. Soon, Giles recorded another entry, where he said about how Stacey had actually been a love wraith from the planet Succuba. Fortunately for him, Maxie made a "concoction" which counteracts Stacey's pheromones, the power that allowed her to alter Giles' perception. Giles spoke about how when he was at a debriefing with Sir Andrew, who was surprised at how naive Giles had been. (WC: Case File - Stacey Facade)

In late November 2020, P.R.O.B.E. received directions from the British government to investigate whether a sinister conspiracy was responsible for lockdowns. Though he found the government's suspicions to be laughable conspiracy theories, he did decide to investigate whether any supernatural forces were involved in the pandemic, and found that one of the Jovian Diplomacy Service's files on the pandemic was locked even to his high-level access code as P.R.O.B.E. director. He rang up one of his contacts at MI6, Jim, who claimed that he started being followed as a result of Giles's call.

On 7 December, Jim, who had stopped replying to Giles's calls, abruptly sent him a text message saying simply "Got the virus". Finding the message out-of-character, Giles decided to go to Jim's house on the off-chance and found that an alien smell like burning sugar was emanating from his front door, as well as an eerie pink glow. He discovered that Jim had been glued to a kitchen chair in his home by a mysterious pink slime which soon enmeshed him as well, causing him to lose consciousness. He was unexpected rescued by Liz Haggard, who had realised that the slime was part of, or under the control of, an alien entity from a parallel universe. The entity explained that the breaches between Ecto-Space and the Earth had been opened by the U.S. government and it was simply trying to repair the cracks using the slime, a kind of cosmic "sticking plaster".

With Control's men admitting their guilt in the matter and begging P.R.O.B.E.'s help to deal with the help they had caused, Liz and Giles were called to New York, where they met Control at his office. He showed them the alien device which they had found and misused, resulting in the cracks in reality. Left alone with the device, Giles received a call from Maxie claiming that the breaches in reality in the U.K. were getting worse than ever. Recognising the type of device from her experience with extraterrestrial technology, she talked Giles through the process of disarming it over the phone. They then returned to London, taking the device with them with Control's permission, and by the time of the New Year's celebrations (for which Liz stuck around) Maxie had figured out the object had drifted to their universe from Ecto-Space. (HOMEVID: Goo!)

Physical appearance
Giles was a fair-skinned man with light brown hair which he tied in a ponytail. He had dark blue eyes and, during the Paul Reynish affair, sported a short beard. (HOMEVID: When to Die) He later shaved it. (HOMEVID: Goo!, etc.)

Personality
Giles described investigation as his passion. Although he was lucid about the untrustworthiness of conspiracy theories, he could not stop himself from investigating them, on the off-chance that something true might be uncovered in the process. (HOMEVID: Goo!) Giles was drawn to the strange and the unknown, being delighted to meet an alien girl (PROSE: She Came From Another World!) and quickly becoming friends with Lor Anderson, a psychiatrist who had spent ten years on the run as a human-shapeshifter hybrid. (HOMEVID: Lauren Anderson) He did not drink alcohol. (HOMEVID: Goo!)