Seven people receive invitations to a ‘singular experience’ during a weekend in Cornwall in a castle reputedly built on the site of King Arthur’s, and situated on an island tenuously connected to the mainland. The sinister host announces that a murder will be committed that night, invites each person in turn to attempt to pull out a sword embedded in a stone, and shows them a golden chalice which he claims is the Holy Grail sought by the Knights of the Round Table. Thus begins a nightmarish series of events, including and impossible murder, the disappearance of the Grail, and communication with the mainland cut off. Has the vengeful king indeed returned? And is there any connection to the recent release of the host’s homicidal half-brother? The plot, one of Paul Halter’s most convoluted, is great fun.