End of term at Castrevenford School. The great excitement on the horizon - the production of 'Henry V' for Speech Day. Luscious young Brenda from the nearby Girls' School is playing Katharine. A natural flirt, she is soon leading on her leading man and a surreptitious meeting in the Science Building is planned. But when Williams arrives, Brenda has disappeared; a cupboard has been broken into; and dangerous chemicals stolen. Then the English master is shot through the eye! The second victim is the French master, shot through the head. Luckily for justice, Gervase Fen, Professor of English Language and Literature at Oxford University and keen amateur detective, is visiting for Speech Day.