A ruthless kidnapper holds a supermarket chain to ransom by threatening the life of a young boy.

The body of Lemmy Hoxton, a small-time burglar, is found at an abandoned farm. There is a spate of break-ins where the intruder gives the sleeping children injections, which reminds Frost of a similar series a few years earlier. A man returns home late one night to find his children dead and his wife missing. Frost's investigations make as many demands on his compassion as on his professional expertise, and he makes a serious error of judgement.

Frost investigates two domestic cases. The first is the tragically straightforward murder of a cantankerous old man by his wife. The other is a more cruelly deceptive one, in which a man is killed, and his son and one of his daughters go missing: Frost tracks them down to Blackpool, where she has gone for an abortion - but who was the father? The answer leads him and DS Barnard into a tragic confrontation with an armed and dangerous paedophile.