Double, Double (Ellery Queen Detective, #21)

Ellery returned to Wrightsville to solve the mystery of: A rich man (believed poor) who died of "old age." A poor man (believed rich) who committed suicide. A scholarly drunk who disappeared. And shortly it occurred to Queen that the puzzle had a pattern. A twisted mind was committing murder according to an old nursery rhyme! Doctor, lawyer, merchant, chief...and to at least one person in town, the chief was Ellery Queen!