A toboggan slide of fantasy -- with Manhattan attacked by a mysterious malady, a fever bringing happiness, disinclination for work, amorality to all who contract it. The story is Commissioner Rowan's search for his wife, Niobe, who vanishes with the fever, and his organization of the city against the dangers of the mass infection. Both jobs provide a springboard for many a relevant, and irrelevant, fact, fancy, character, incident, for Niobe is spotted in various disguises, all over town, and the search for the cause, and cure, of the disease brings in a detailed blueprint of civil departments and their workings. Rowan, too, catches the fever, is confronted with political opposition, has his personal troubles with the fever's sexual aspects, and is saved, together with the city, by the finding of the cure and the arrival of cold weather. A potpourri of scientific, artistic, musical, literary interpolations that gives this novel a realistic-fantastic appeal. Interestingly different.