'Ten...' Ten strangers are lured to an isolated island mansion off the Devon coast. 'Nine...' In the drawing-room after dinner a recorded message accuses each of them in turn of having a guilty secret, and by the end of the night one of the guests is dead. 'Eight...' Stranded on the island, they are haunted by an ancient nursery rhyme counting down one by one...as one by one they begin to die. 'Seven...' Which amongst them is the killer and will any of them survive?