Chrissie

"Chrissie" is the fourth series' most uncomfortable hour — a story about a lost teenager that ends in a way the series had never dared before. Chrissie Barker, fourteen years old and in foster care, has run away to Jersey, telling a story about looking for the seaside house of an aunt she remembers from childhood. She is taken up by the island's fringes: Louis, a young motorcyclist on the beach, and the Demoins, a fashion-designer couple whose daughter Michelle has befriended her. Meanwhile Rod and Trace, two rough teenagers, are stealing handbags and briefcases from cars, and the series quietly builds a picture of a summer of small crimes.

Karen Dotrice — the Mary of Mary Poppins, now grown — plays Chrissie with a brittle, watchful volatility that keeps the audience uncertain whether she is victim or manipulator. Edwin Pearce's script, directed by David Reynolds, is careful with her: the police discover she has a history of instability, that her mother abandoned her and her father died a month ago, and that her foster parents have reported her missing. The Demoins, absorbed in their Paris show, hired her without checking references; the episode does not spare them.

What follows is a chain of bad luck with a terrible end. Chrissie's great-aunt Anne, who barely knows her, contacts the foster parents; the police close in; and when Chrissie runs to join Louis on his motorbike, she sees Michelle about to run into the road, turns back — and is hit by a car and killed. The death is sudden, casual and entirely believable, and the episode lets it land without music or sentiment.

The aftermath is a radio debate between Hungerford and Crozier, blaming each other for the girl's death, while Bergerac listens in his car and turns it off, looking out to sea, haunted. It is the series' most direct statement about the cost of small failures — a child no one really looked after, killed at the end of a summer of petty crime. A grim, necessary hour, and one of the fourth series' most memorable.