The third Jan Christopher Cosy Mystery Was murder deliberate - or a tragic mistake? January 1972. The Christmas and New Year holiday is over and it is time to go back to work. Newly engaged to Detective Sergeant Laurence Walker, library assistant Jan Christopher is eager to show everyone her diamond ring, and goes off on her scheduled round to deliver library books to the housebound - some of whom she likes; some, she doesn't. She encounters a cat in a cupboard, drinks several cups of tea... and loses her ring. When two murders are committed, can Jan help her policeman uncle, DCI Toby Christopher and her fiancé, Laurie, discover whether murder was a deliberate deed - or a tragic mistake?