A case of deadly poisoned chocolates from a high street shop haunts the group of friends and relatives assembled at Bellegarde. Owner Marcus Chesney wants to prove a point about how the sweets could have been poisoned under the nose of the shopkeeper and he stages an elaborate memory game. But during the test Chesney is murdered. The keen wits of Dr Gideon Fell are called for to crack this bizarre murder committed in full view of an audience. Widely regarded as one of John Dickson Carr's masterpieces.