Adam (Doctor Who)
Adam was a participant in a plan to colonize another world. His real name was Nigel Castle. Prior to joining the program, he had been a novelist. He along with Ruth and Mark was one of the three people aboard what the group thought was a spaceship three months on its way to a new, Earth-like planet, where he hoped to begin a new, pollution-free life.
When Sarah Jane Smith ended up aboard, claiming to have been brought there against her will, nobody believed her, least of all Adam. However, when frequent visits to the Reminder Room failed to bring her around to the colonists' way of thinking, a worried Adam, wondering why someone so different from them would've been selected, contact Charles Grover on a neighboring ship, little suspecting their own "ship" was just an elaborate facade built underground, and demanded an explanation. Grover, in reality only a few rooms away, put on a spacesuit and entered, hoping to reassure the colonists.
Most of the others were convinced, including Adam at first. However, he overheard Grover talking to Sarah Jane and Mark in the Reminder Room, where Grover didn't deny Sarah's accusations. Adam realized that Grover was tricking them. After Sarah proved to everyone that they weren't really on a spaceship, the fearful and enraged colonists stormed Professor Whitaker's laboratory, intending to stop Operation Golden Age and bring Grover to account, with Adam insisting that what Grover planned to do was worse than murder.
At the same time, the Doctor also entered with UNIT and the Brigadier. Refusing to give up, Grover activated the Timescoop, but accidentally sent himself and Whitaker back in time instead of the entire planet. Presumably, Adam and the other colonists returned to their normal lives and their real names.