When police are called to a house in Chelsea, to investigate complaints of a noisy party, all is quiet, but flames are seen coming from the house a short while later. The fire brigade discover the body of Mrs Diana Barton, who has been stabbed to death in a frenzied attack. DCI Brock and DS Poole investigate, and they soon discover that the party was less than respectable, and that Diana Barton's death is just the first . . .