The Treatment is the second in Mo Hayder’s Jack Caffrey series. Caffrey is still obsessed with the paedophile next door and the mystery of what happened to his brother all those years ago.

Caffrey gets a case that seems a little too close for comfort. A family is held prisoner in their own home for a weekend. No one notices because they were supposed to be going on holiday. Instead, the mother is restrained and locked in a cupboard, the father is restrained on the landing while the son is abused. Then the perpetrator takes the child out of the house and is seen by a passerby. The police sweep the area but can’t find anything.

Whilst investigating this case, Caffrey is also trying to work out what happened to his brother. The cases are linked and Caffrey gets information that takes him out to a remote farm in Suffolk. Some of his actions are ill-advised and Caffrey is risking his job to pursue his obsession.

An extra complication is that Caffrey is dating one of the women that was a victim in the last book, Birdman, and she’s dealing with her experiences in a very public way. His secrecy and obsession with his brother isn’t making things between them better.

The plot twists and turns and the killer is hidden in plain sight. There are a few plausible candidates and Hayder shows how easy it can be to miss what is really going on. I wasn’t keen on the heavy-handed use of dialect for the character of Caffrey’s boss but that was the only thing that spoilt my enjoyment of the book. The resolution of all the plot lines was brutal and I found it very affecting.