Shadowplay (1)

A young woman with a history of psychiatric problems burns her family alive in the house, then hands herself in without much fuss. She admits the whole thing. What she will not accept is sole responsibility: she says she was coerced into it by a figure known only as The Shepherd. Shadowplay (1) starts from that claim and spends the hour deciding whether it is madness, manipulation, or something worse.

Her psychiatrist does the useful thing and links her case to others like it in the district, which brings in the Cold Case Squad. Once Boyd and the team start pulling the threads, the picture darkens. Two women with psychiatric problems driven to murder, a third driven to suicide, and the same shadowy religious figure apparently standing behind all of them. The evidence is thin and mostly lives inside damaged heads, so this becomes a case about psychology as much as forensics. Grace Foley's territory entirely.

Barbara Machin and Ed Whitmore wrote it, Andy Hay directed. Trevor Eve is Boyd, with Sue Johnston as Grace, Holly Aird as Frankie Wharton, Claire Goose as Amelia Silver and Wil Johnson as Spencer. Around them: Paul Kaye as Dr David Carney, James Larkin as Dr Matt Carney, Lucy Gaskell as Fay Harding, Laurence Penry-Jones as Adam Duke and Eve Best as Natasha Bloom.

Part one is deliberately unsettling because it never lets you settle on an answer. If the woman is deluded, a family is dead and nobody else is to blame. If The Shepherd is real, someone out there is hunting vulnerable minds with scripture and patience, and has not finished.

Eve Best is the reason to watch. She makes the coercion feel plausible, which is the scariest available option. A voice only she hears, instructions only she receives, and suddenly a confession stops being an ending and becomes a question mark. Boyd treats it as a lead; Grace treats it as a symptom, and neither can prove the other wrong.

Part one closes without settling any of it, which is exactly right for this story. The Shepherd stays a rumour with a body count.