The Treatment — Mo Hayder

Now a major motion picture: A boy's abduction reawakens a haunted past for British detective Jack Caffery in this “deliciously chilling thriller” (Publishers Weekly, starred review).
 
In a quiet residential area in London, a couple is discovered bound and imprisoned in their own home. Savagely battered and severely dehydrated, the worst revelation is yet to come: Their eight-year-old son has been abducted.
 
When the boy's body is found, forensic evidence reveals disturbing parallels to events in Det. Jack Caffery's own past. As more evidence accumulates, Caffery struggles to maintain his professional distance. But the case is hurtling toward a terrifying conclusion that will force him to confront the demons he's tried so hard and so long to bury . . .
 
“The most frightening book I've ever read.” -- The Guardian
 
“Hayder handles procedural detail, dialogue, and volatile subject matter with powerful dexterity.” -- Publishers Weekly, starred review