On a beautiful summer's day, at a remote lake in the middle of Dartmoor, three members of the Fowler family take a dinghy out onto the water, leaving mother Sarah at the shore.

Less than sixty seconds later, she checks to see where they are. The boat is drifting in the middle of the lake. It's empty.

Sarah's family have completely vanished.

At the Skyline Casino in London, the security team have just made a headline-grabbing arrest: they've spotted and detained a man suspected of murdering a high roller. After locking him in one of their holding cells, the team station themselves outside and wait for the police.

But when the cops arrive, they find something impossible. The killer is no longer inside the cell.

David Raker is an expert at solving missing persons puzzles – but these mysteries are unlike anything he's ever seen.

As he digs into the Fowler's, his long-time ally – ex-detective, Colm Healy – tries to get to the bottom of what happened at the casino. But the men are in danger. Because, buried in the shadows of both cases, is a deadly secret that was never meant to come out .