Little Boy Blue

Eight-year-old Alec Browell lives with his gran. His mother does not want him, and when he disappears, nobody reports it to the police for more than a day. That lost day is the whole story. By the time anyone says the word missing, Watt has no choice but to open a murder inquiry, because a child gone that long without a word is a child the police have to assume is dead. The title is a nursery rhyme, which makes it worse.

The episode sits with the weight of that. The investigation runs under the shadow of a delay that should not have happened, and the questions turn on the family as much as the case. Watt, Hawkins and Evans carry it, with Snow out on the ground, and the Browell household is drawn in careful detail: Helena McCarthy's Gran Browell, Deirdre Costello's Sue Browell, the mother who did not want him, and Katherine Parr's Mrs Byatt. The women are not monsters; they are people who failed to notice, which is worse.

Ellis Dale's Thomas Byatt and the boy's friend Morris, played by Raymond Witch, fill in the edges of Alec's small world, and Wally Thomas's Simms does his bit. The absence at the centre of it is a child, and the episode never lets you forget it.

Elwyn Jones and Allan Prior wrote it, Matthew Robinson directed, and the handling is restrained in the way this sort of material demands. There is no comfort to be had in the ending, and the episode does not pretend otherwise.

But the chill is in the silence that preceded the search. A child who is not wanted, a family that does not notice quickly enough, and a chief superintendent forced to treat the worst case as the only working assumption. It is careful, sombre television, and it earns its mood.