Anonymous poison pennings at Prior's Umborne cause Sir Archibald Blick to hire Nigel Strangeways to locate the evil-doer and restore the town's sanity. The Chantmerle sisters (one crippled), Blick's two sons and dusty doings in the village put Strangeways beyond official rules and test his bluffs. Blick's murder confounds the confusion until Strangeways surprises proof positive. Broody.