The Big Crunch (1)

A girl goes missing for days, and when she is found she is naked and marked with strange symbols, quoting the Bible. The trail leads to a fringe Christian sect and its leader, Kenneth Trant, a man who runs his little kingdom on charm and certainty. One of his congregation is Joanna Barnes, a schoolgirl, and she is sleeping with him. The symbols on her skin are the first real clue, and nobody in the squad knows what to do with them.

The affair is the crack in the whole edifice. When it comes out, Trant and his lieutenants abduct Joanna rather than face it, and the police, reluctantly, call in Fitz. The call to Fitz is reluctant, because the police hate needing him almost as much as they need him. Then Trant's wife and sister learn Joanna is pregnant, and the sect's fury turns into a vendetta that ends in attempted murder. The abduction happens in daylight, which makes it worse.

Jim Carter's Trant is the kind of villain who never raises his voice, which makes him worse. Samantha Morton's Joanna is the frightened centre of the story, and Cherith Mellor, Maureen O'Brien and James Fleet give the family their unsettling quiet. Whitehead wrote it, Julian Jarrold directed it, and the episode takes its time letting the horror of the community settle in. Barbara Flynn's Judith has her own scenes, because even here Fitz's home life refuses to stay in the background. And the girls who stayed in the sect watch it all happen, their silence one of the creepiest things in the episode. The episode is patient with its cult, showing how the group swallows ordinary people whole.

The police want Joanna back. The sect would rather she simply not exist. And Fitz is the only one asking why anyone joined in the first place.