Spooks

A computer hacker threatens to breach MI5's firewalls, putting the lives of two cornered agents in Pakistan at risk. When Section D suspect Gordon Blaney, a member of the Socialist Freedom Movement, an anti-government group, Zoe is tasked to go undercover as a teacher in the same comprehensive school Blaney teaches. Meanwhile, Danny Hunter works to infiltrate a left-wing newspaper where the socialists operate. It is later revealed that Blaney and the socialists were elaborately framed by the hacker, pupil Noah Gleeson. Noah is the son of Victor Gleeson, a former MI5 officer stationed in Greece; the boy underwent a psychotic break after witnessing Victor's murder. Now guided by the hallucinations of his dead father, Noah occupies Section D with a threat against the school as a diversion to gather Malcolm's access codes for MI5's "inner sanctum" (its mainframe). Tom and Zoe are able to stop him from succeeding, and Noah is apprehended and sent to a psychiatric hospital.