Lieutenant Carl Sarabia, a newly retired homicide detective, moves with his wife, Greta, from Houston, Texas, to Glamis, Connecticut, to be closer to their daughter, Sarah, and her family. The idyllic river town is upended when Merlin Glenmore is found murdered on April Fools' Day, midway through his seance-themed birthday party at the place he despised the most, The Glenmore-Pace Castle, a gothic mansion built by his great-great grandfather, and now a museum run by his sister, Jade. Merlin is notorious in Glamis for his abrupt second marriage to a much younger woman only a month after his first wife's tragic death. There is no shortage of suspects present at the party who wanted Merlin dead. Only two of the guests do not have alibis --- and one of them is Carl's son-in-law.