Murder is not considered an essential part of the curriculum - even at a modern English preparatory school; nor did Shakespeare intend Twelfth Night to have a tragic ending. But when the curtain falls after the performance on the first evening of the half-term weekend, one of the cast lies dying a most unnatural death - Sir Toby Belch, who had played the drunk scene in the last act with brilliant realism.

Most members of Shakespeare Players Ltd. suspect Lionel Basset, whose arrival in the troupe heralded an outbreak of petty theft. Yet Sonia Fenton behaves quite unpredictably when she learns of her husband's "accident," and Edward Gash, the most talented among them, is oddly embarrassed by the huge bruise on his arm. Inspector Mitchell of Scotland Yard finds he must make a quick study of Twelfth Night. And with the help of young Bruce Pritchard and Dr. Winthringham - who quietly speculates on the possible effects of internal hemorrhage - the inspector arrives at a startling solution to this enigmatic murder.