In an overcrowded Stockholm underground station a father and his two boys are late for their train. Joel, the youngest, is howling in his pushchair and his seven-year-old brother, Kristoffer, refuses to take the lift.

A woman approaches and offers to lead Kristoffer up the stairs. Reluctantly his father agrees, but when he arrives on the platform Kristoffer and the woman have vanished without a trace.

Many years later, Joel, now an adult, goes missing in suspicious circumstances. His wife turns to Danny Katz - an old friend - for help. But Katz isn't the only one trying to find Joel, and the deeper he digs the more secrets he uncovers about the wealthy and powerful family at the heart of the investigation. Then suddenly, the case takes a dramatic new turn.