Pandora's Many Boxes

The whole case hangs on a single failed security check. A man is refused clearance, or should have been, and Bulman is asked to work out what that means. On paper it is paperwork. The check itself is the mystery: who failed and why, and what they were trying to get past. In practice, a routine check turns out to be the kind of thing that hides a body or a fortune, and often both, and the episode has the good sense to keep the reveal small and domestic.

But it is a contained puzzle, closer to a day's office work than a manhunt, and it suits Henderson's Bulman, who enjoys a problem he can hold in his head. DS Derek Willis and DCI Faulkner drop by to keep the police side honest, Dennis Blanch and Jeremy Gagan playing the procedural counterweight to Bulman's civilian approach. Their scenes are brief, but they do what recurring characters are supposed to do: they remind you that the old world is still running alongside the new one. There is a quiet pleasure in watching a small mystery treated with full seriousness.

Murray Smith wrote it and Christopher King directed. It is the sort of hour that lives or dies on small exchanges, and this one lives. The security check turns out to be a door, and what is behind it is worth the walk.

Siobhan Redmond's Lucy McGinty is on hand as ever, which is worth saying because these quiet episodes would be thin without her. She provides the second opinion that Bulman's confidence needs, and she is never allowed to become a sidekick. They read each other's silences by now, and the episode depends on that shorthand. The partnership is the point.

Pandora's box, in the myth, let all the troubles out. This one mostly stays shut, and the episode is better for its restraint. A small pleasure, but a real one.