Miss Lucy Pym, a popular English psychologist, is guest lecturer at a physical training college. The year's term is nearly over, and Miss Pym -- inquisitive and observant -- detects a furtiveness in the behavior of one student during a final exam. She prevents the girl from cheating by destroying her crib notes. But Miss Pym's cover-up of one crime precipitates another -- a fatal "accident" that only her psychological theories can prove was really murder.
Josephine Tey began writing full-time after the successful publication of her first novel, The Man in the Queue (1929), which introduced Inspector Grant of Scotland Yard. She died in 1952, leaving her entire estate to the National Trust.