Flippy the canary reads a book on crime, and sees his cage as a cell and himself as stir-crazy. He escapes, only to be pursued by his enemy, the cat, now a prison guard.
After the discovery of two murders, Commissioner Chabrier, of the French secret services, is investigating the disappearance of plans affecting the national defense of the country robbed by a gang of international spies.
Stevie Carson, a newspaper reporter, and Danny Butler, the "morgue" manager on the same newspaper, set out to track down the killer of a colleague, a book-reviewer who was involved with a group of rare book forgers and whose sister has been convinced her editor-fiance, Bill Monroe, killed him.
Maggi continues her forever-ever efforts to crash Manhattan's top society, while Jiggs still mingles with his old construction cronies at the bar of Dinty Moore on 10th Avenue.
A virtuous Spanish princess becomes queen of Portugal, and soon is affected by the social struggles and the reckless fight to power between the king's faction and that of his son's.