Pet Mystery Week brings brisk business to Penelope McClure's Rhode Island bookshop, but a real mystery comes barking at her door, when a lost dog turns up in a panic. Pen and her son, Spencer, follow the furry fugitive, Lassie-style, to a wooded area where the dog's owner lies unconscious. Mrs. Cunningham is a beloved member of Quindicott's community, a warmhearted widow who volunteers at the local animal shelter and runs Buy the Books' pet-lovers book club. Why would anyone shoot such a sweet soul? The police believe it is an accident, a shot by a careless deer hunter, but Pen is not rolling over. To straighten out this doggone mess, she whistles for the ghost of PI Jack Shepard, an expert in hounding as well as haunting. Jack has a shaggy-dog story of his own, a case from the 1940s that may help Pen sniff out clues to her present predicament. Yet even with Jack's hard-boiled help, Pen is not able to catch the killer before he pounces again. It seems the whole case may be going to the dogs...