Slight Mourning — Catherine Aird

INSPECTOR SLOAN MUST FIND THE KILLER AT THIS "LAST SUPPER" AT A COUNTRY HOUSE

At first it seemed like just another automobile death for the perennially melancholy Inspector "Happy Harry" Harpe of the Berebury traffic division to deal with: a local magistrate, Bill Fent, driving an aged dinner guest home and meeting with a fatal accident on his return trip. But when the police pathologist finds barbiturates in the victims blood, it becomes a case for Inspector Sloan of the C.I.D. Twelve guests had been present at a dinner party at Fent's country house, Strontfield Park, but only eleven survived the excellent meal they had been served. Now all are suspects, unless Sloan can find who would want to murder a man whose estate was so heavily entailed that there was no apparent financial motive for killing him. Laced with the author's usual dry wit, it's Aird's seventh mystery and the sixth to feature Inspector Sloan and his incompetent assistant Sergeant Crosby. First published in England in 1975.