More than a year after Mark's disappearance, the bodies of two boys are discovered in Essex, five days apart: Jason Swift was 14 and Barry Lewis just six. Police quickly link the deaths and launch a complex investigation called Operation Stranger.

The conclusion to the abduction of seven-year-old Mark Tildesly that reveals the depravity of the child abusers who snatched him from a Wokingham funfair in 1984.