It's been thirty years since they witnessed the accidental drowning of their friend.
Those who were present – now parents themselves – have begun to receive messages claiming to be from the boy who died.
The troubling notes become more alarming when a child disappears.
Time is running out for Detective Inspector Jack Munday as he balances the sensitive case alongside personal problems and a demanding new superior officer.
In the maelstrom of head-versus-heart, one thing is certain; whoever is sending the messages wants revenge.