For 50 years, a group of friends have been meeting regularly for reunions on Holy Island, celebrating the school trip where they met, and the friend that they lost to the rising causeway tide five years later. Now, when one of them is found hanged, Vera Stanhope is called in. Learning that the dead man had recently been fired after misconduct allegations, Vera knows she must discover what the friends are hiding, and in this tenth outing (after The Darkest Evening), Vera is in more danger than she could have believed possible.