Nancy and Calder are moving from London to an isolated slate island, off the west coast of Scotland. Nancy is focused on their new beginning, but is increasingly unsettled by the stark island, the mysterious inhabitants and Calder's dark past, which he's kept hidden from her. Then one of Nancy's nightmares plays out in real life: she finds Calder's boat upturned in the bay, his body adrift in the icy water.

He's clinically dead with no heartbeat. But miraculously the doctors manage to bring him back to life. Everyone thinks he has made a full recovery, but Nancy doesn't recognise the man who has come back from the dead.

As secrets, lies and bodies begin to wash up on the island, Nancy must come to terms with the fact that despite the fresh start, sometimes the slate cannot be wiped clean.