Peter Davison plays Margery Allingham's enigmatic 1930s sleuth Campion, who's aided and abetted by Brian Glover, his slightly shady manservant. An English country house, old money, good breeding and a brutal and bizarre murder conspire to create just the sort of mystery for Campion to unravel. No sooner does he begin his investigation, however, when another member of the family, dear Aunt Julia, is poisoned.