"The Inquisition," the requisite "flashback" instalment of all Gerry Anderson series programmes, is an instalment of Captain Scarlet And The Mysterons, and indeed the thirty-second and last ever to be produced and/or transmitted during the programme's original run
A Mysteron likeness of a Spectrum Intelligence agent named Colgan tries to manipulate Captain Blue into revealing the Spectrum cipher codes, so that the Mysterons can carry out their threat that "One of the members of Spectrum will betray you all."
Paul Metcalfe and Adam Svenson have had a good meal at a restaurant called "The Markham Arms," in a location the instalment does not specify. Before they leave, Svenson is served some coffee that he has ordered. But immediately after drinking it, he feels strangely sick, and he disappears as Metcalfe is retrieving their coats.
Svenson recovers consciousness to find himself aboard what resembles Cloudbase's Control Room, with a man calling himself Colgan, and claiming to be a member of Spectrum Intelligence,
He tells Svenson that he has been unconscious for three months and demands that he prove his identity by providing the Spectrum cipher codes.
"All you have to do is prove who you are," Colgan says.
Svenson refuses to do this, even though he does partially describe three of his and Captain Scarlet's shared experiences ("Big Ben Strikes Again!", "The Trap", and "Crater 101") against the Mysterons.
Getting nowhere, Colgan calls his aide, who is carrying a hypodermic needle containing a truth serum in one hand and a pistol in the other. Colgan gives Svenson one last chance to give him the cipher codes, but Svenson jumps out the window to discover that the setup is false, and Captain Scarlet's voice--one Svenson is glad to hear--orders him to get clear, whereupon Captain Scarlet manages to destroy the building inside which Svenson was being held prisoner, using missiles that he launches from a Spectrum Pursuit Vehicle.
Captain Scarlet asks his friend if he is all right, Svenson replies that he's fine and asks if they were Mysteron agents. Captain Scarlet replies, "Yes" and explains that it had taken a few hours for the Spectrum Organisation to locate him, but had barely made it in time.
Svenson is annoyed that he had nearly been fooled, but Captain Scarlet cheers him up and says, "You can tell me all about it...back on the real Cloudbase."
- This is the only instalment in which neither Colonel White nor the real Cloudbase appear.
- In 1993, the instalment was also a small paperback in a series of eight books, written by Graham Brown, illustrated by famous artist Richard Chasemore and published by Boxtree, with the title Mysteron Trap. The cover itself is a flashback of the instalment Crater 101, one of the adventures that Captain Blue tells to Colgan to prove his identity.