Brewster's first encounter with the Doctor was at his mother's funeral in, where the Fifth Doctor and Nyssa were travelling down Thomas's timeline in order to remove his psychic link to a potential future.
After his mother's funeral, Brewster was enrolled into an orphanage, where he stayed for around 10 years. There, he began to have visions and dreams of his mother, which were in actuality a being from a potential future trying to make their future a reality.
In 1865, Creek was visited by The Fifth Doctor and Nyssa, who enquired about Brewster. Creek assumed that this meant Brewster was valuable, so he intended to sell him. Creek then drowned in an accident, and Brewster and his friend Pickens left to start a new life. It was then where the being from the potential future first directly contacted him, and began to instruct Brewster in doing deeds to aid it in becoming an actuality. The most important being the theft of parts to build a time machine for the being. (AUDIO: The Haunting of Thomas Brewster)
Meeting the Doctor
Brewster's first proper meeting with Nyssa was in 107 Baker Street on 14 November 1867, while he was attempting to steal an Electromagnetic field generator for his time machine. Working with Pickens, he kidnapped Nyssa, and stole the generator. He eventually completed the makeshift time machine, however Pickens was killed. Brewster, Nyssa and the Doctor then reunited, and regrouped at Baker Street. There, the Doctor developed a device to stop the alternate future becoming a reality.
The being continued to instruct Brewster, forcing him to break the Doctor's device, steal Nyssa's TARDIS key, and pilot the TARDIS to the alternate 2008. The Doctor and Nyssa then used the TARDIS Brewster had found in 1861 to rescue him from 2008, and finally prevent this future from coming true. Then, to prevent Brewster dying with it, they travelled with him up his timeline to remove the psychic link with the future.
After fainting, following an encounter with his past self, Brewster was left alone in the TARDIS in back in 1867. Worried that he'd be left alone on the streets once more, he stole the TARDIS, leaving the Doctor and Nyssa stranded. (AUDIO: The Haunting of Thomas Brewster)
Brewster gained limited control over the TARDIS. On one of his stops, the TARDIS was taken from him for ransom and he was forced to work for the Doctor's old enemy, Gerry Lenz. At this time, Brewster met the Doctor's old friends, Brigadier Lethbridge-Stewart and Polly Wright. The three of them rescued the TARDIS from Lenz and saved the Earth from dying and from a Coffinloader, a beast which fed on dying worlds. (AUDIO: The Three Companions)
Eventually, the TARDIS began to malfunction due to Brewster's meddling. Before the ship could come to any further harm, Thomas was helped by an elderly Adric, who got him back to London a few months after his departure. The Doctor invited him to join him on his travels (AUDIO: The Boy That Time Forgot) but soon after he joined, they returned to the location of one of his previous travels, where it was revealed that Brewster had sold several vital components of the TARDIS to the marooned crew of the Gamma. Among the components Brewster sold was the TARDIS' conceptual geometer, the removal of which greatly destabilised the structure of the TARDIS and eventually caused the collapse of the ship's internal dimensions. However, the Doctor was able to reconnect the geometer to the TARDIS, restoring its interior to normal. (AUDIO: Time Reef)
Leaving the Doctor
After they left, Brewster convinced the Doctor to take him to 2008 supposedly to see his future. In fact, he wished to be reunited with a young woman named Connie Winter, whom he had met whilst travelling in the Doctor's TARDIS alone. Thomas decided to stay in 2008 with Connie rather than continue travelling with the Doctor and Nyssa, and the Doctor let him use his house in 107 Baker Street. (AUDIO: A Perfect World) During his ownership of the house, Brewster had it subdivided into five flats, using loans taken out against the property to cover building costs, and used a letting agent to rent them out. (AUDIO: Lost Property)
Reunion with the Doctor
Brewster enjoyed his life with Connie, but tragedy struck. She was hit by a car and suffered an irreversible coma. Alone in a time when he didn't fit, Brewster found the time machine he had built while under the control of the alien pretending to be his mother in 1867. He was trying to return to his own time when he was contacted by Symbios, a sentient planet which was being invaded by an alien robot species called the Terravore. Brewster provided Symbios with hosts who were riding the tube. After defeating the Terravores with the Doctor, now in his sixth incarnation, Evelyn Smythe and DI Patricia Menzies, Brewster stole the TARDIS key, snuck aboard and held the Doctor and Evelyn at gunpoint, demanding they return him to his own time. (AUDIO: The Crimes of Thomas Brewster)
Instead, the Doctor managed to disarm him and planned to hand him over to Menzies, but the TARDIS was drawn to Axos, which was trapped in a time loop. Brewster helped the Doctor defeat the Axons, and the Doctor, at Evelyn's behest, decided to return him to his own time.. (AUDIO: The Feast of Axos)
The Doctor got Brewster a job at a factory, when the machines started coming to life as a net result of a sentient device brought to Earth by an illegal alien trader named Samuel Belfrage. Brewster eventually destroyed the device and all the creatures it created, an action over which the Doctor was both dismayed and furious. Despite Evelyn's protests, the Doctor refused to take him with them and angrily proclaimed that Brewster had wasted his last chance before leaving in the TARDIS without him. Brewster arrived to apologise just as the TARDIS dematerialised. However, he went on to travel and begin a business partnership with Belfrage, who had collected all of the illegal product which the Doctor had intended to relieve him of. (AUDIO: Industrial Evolution)
Brewster was charming (AUDIO: The Haunting of Thomas Brewster) and considered dangerous, deceitful and sly by the Axos. (AUDIO: The Feast of Axos) He used to feel bitter about his mother's death and wished that he had done something. (AUDIO: The Haunting of Thomas Brewster) He was willing to risk his life to save the Doctor (AUDIO: Time Reef) but was also happy to pull a gun on him, (AUDIO: The Crimes of Thomas Brewster) albeit one without ammunition, to get what he wanted. (AUDIO: The Feast of Axos)
Evelyn Smythe thought that Brewster meant well and had good instincts once he'd found his place but the Sixth Doctor was convinced that he chiefly sought to protect his own interests and thought he knew best. (AUDIO: Industrial Evolution)
Being born with very little, Brewster had a strong proclivity for theft, which he demonstrated by taking the Doctor's TARDIS key from him on multiple occasions and even stealing the TARDIS itself from the Fifth Doctor twice in a row. (AUDIO: The Haunting of Thomas Brewster) When ending up in situations wherein he is far out of his depth, Brewster is quick to resort to any method to preserve himself or turn the scenario to his advantage with little to no regard or forethought to the consequences that his get-out-of-jail antics would entail. (AUDIO: Time Reef, Industrial Evolution)
Behind the scenes
- Brewster is one of only four companions created by Big Finish to travel with two incarnations of the Doctor, namely the Fifth Doctor and the Sixth Doctor. The only other Big Finish created companions to have travelled with two Doctors are Evelyn Smythe, who served as a companion of the Sixth Doctor for several years and met the Seventh Doctor in Thicker Than Water and A Death in the Family, Charley Pollard, who travelled with the Eighth Doctor before travelling with the Sixth Doctor, and Liv Chenka, who met the Seventh Doctor and later travelled with the Eighth Doctor. (AUDIO: Robophobia, The Traitor)