At Elysian Hall, a great exhibition space in post-War London, a cast has been assembled for a Medieval pageant show. Tragedy is in the air when several members of the troupe are sent death threats before the show, and the worst comes to pass when one of the players is found dead - killed during the performance. Inspector Cockrill and Inspector Charlesworth adopt the case, rivals in a race to answer the impossible question: how could it have been done? A British Library Crime Classic.