When a murder takes place in the sleepy market town of Bakerbury, the local police are baffled by a crossword puzzle left on the body. With their case going nowhere, they turn reluctantly to Cora Felton, a recent arrival in Bakerbury, whose fame as the eponymous “Puzzle Lady” suggests she can help DCI Hooper and the Bakerbury police unravel the crossword clue and solve its first murder case.