Knock for Knock

Claire Stevens is under general anaesthetic at a dental surgery when she starts talking about the van that killed her husband. The dentist passes on what she said, and Eddie, waiting nervously to go on air for the first time, picks up his first case as the station's Private Ear before he has presented a single programme.

Claire takes him to the spot where a white van crashed into her husband's car six months earlier. Two men were involved, the police never traced them, and the restaurant the couple ran went with him. Eddie asks a local mechanic whether anyone has come in for a respray. The mechanic brushes him off and then hands him a photograph left in the back of the van. The photograph is of a retired army clergyman, and through regimental records Eddie identifies him as the Rev. James Appleby, who with his wife explains that two men called to buy an antique writing cabinet and eventually talked them into selling it.

The cabinet was bought by a pair of knockers, furniture dealers who talk elderly owners down to a fraction of the value, and traced to a shop owned by Barbara Knight. Meeting Knight again at an auction, Eddie realises she has been stalling him so that the van parked outside, by now resprayed blue, can get away. It rams his car and escapes. A second dental appointment gives Claire another detail she could not recall consciously: a third man was badly hurt in the crash and the two men took his body with them. Erica's access to police records establishes that a French polisher was found dead six months earlier. The trail ends in a fight at a garage, with the van, now green, identified and Barbara Knight admitting the two drivers are her sons. She asks Eddie to let it go. He refuses and reports them, on the reasonable ground that his client lost her husband and her business and is owed compensation rather than discretion.

Two things make the episode more than a follow-up. The first is the on-air sequence, which is the clearest single statement of what Eve does with the part: the broadcast goes badly while he reads his script and comes right the moment he abandons it. The second is the knockers plot, the first appearance of a fraud against elderly people that the series returns to repeatedly, and it is treated as the serious theft it is rather than as a curiosity.

Shirley Anne Field's Barbara Knight is neither villain nor victim, which is a harder part than it sounds: a mother who has been covering for two sons who killed a man. The weakness is that the case is resolved largely through institutional records, with the regimental roll and a police file opened off screen by Erica, so Eddie is absent from the work at the point where the audience most wants to watch him. There is also more physical action than the period usually allowed, including a car chase through the sloping Bristol streets and a mud-covered fight, and BFI Screenonline singles the fight out for its use of humour. The episode drew 20.5 million viewers.