Another adventure for the managers of the Carson Street Detective Agency operating out of Belleville, N. Y. (see Mystery of Burnt Hill and Three Stuffed Owls) begins for Swede and Neil when they are offered a ride on a hot summer day by a tall writer in an MG who is looking for Captain Wudge. Offering their services, Swede and Neil are told by the writer that he wants pictures of Captain Wudge's famous chess set for a magazine article he is doing, only the pictures have to be taken in secret because of the controversy the planned article will cause. From this start, the book unfolds into a full and funny mystery complete with the antics of Neil's pet crow Hector, the appearance of thugs who bring on more than was bargained for, and the final discovery of a ruby in one of Capt. Wudge's castles (which Hector dropped down a chimney). Also evident is Mr. Robertson's familiar knack of making something very real and earthy out of the unlikely.