Arthur Cartwright insists on seeing Perry Mason about his neighbor's constantly howling dog. When Mason gets a district attorney to issue a warning to the neighbor, Clinton Foley, Foley claims that Cartwright is insane. Mason nearly starts to believe him when Cartwright draws up a will leaving everything to Foley's wife. That's why he pays a visit to Clinton Foley's house, where he finds a missing wife, a poisoned dog, and a corpse.