Private Lives

A hit-and-run in a quiet village puts charity worker Bryony Darrow into a coma, and Frost — partnered with the blunt DS Billy "Razor" Sharpe, filling in for the ill Toolan — begins peeling back her life like an onion that only gets uglier. The first suspicion falls on Owen Kimble, an ex-ex-ex-soldier with post-traumatic stress disorder who wanders the woods where Bryony was found. But Frost, following her financial trail, makes a discovery nobody expects: the respected charity worker was a sex worker, keeping a flat in London under the name Natalie Williams.

Bryony's mother, Marion, has been living in that flat, asking no questions, unaware her granddaughter Rachel even exists. Frost pieces together the double life: the charity work was a front, the London flat a business, and a solicitor named Graham Rutherford — one of her clients — had been setting up a trust fund for Rachel behind her husband Richard's back. The DNA results deliver the final blow: Richard was the last man to have sex with Bryony, and he confesses. She had left her past behind for him, but when he found her with Rutherford, they quarrelled; she told him she was leaving and taking Rachel. Unable to bear the betrayal, Richard hit her with his car.

The second case is a brewery robbery gone wrong — the safe was empty, the criminals got nothing, and Frost, tipped off by archivist Ernie Trigg's pattern-spotting, sets a trap for the inevitable second attempt, catching career criminal Leo Armfield red-handed.

Private Lives, written by Russell Gascoigne and directed by David Reynolds, is the series at its most corrosive — an episode about how many separate lives a single person can lead, and how many people get hurt when they collide. Peter Egan's Richard, a man destroyed by his own secrets, and Paloma Baeza's Rachel, learning her father is not her father, carry the weight; and in the end, Rachel chooses the grandmother she never knew over the family that lied to her.

A corrosive study of double lives and the damage they leave behind, anchored by Peter Egan's portrait of a man destroyed by his own secrets. A corrosive portrait of double lives.