At first the Sycamores seem mad, but it is not long before we realize that if they are mad, the rest of the world is madder. In contrast to these delightful people are the unhappy Kirbys. The plot shows how Tony, attractive young son of the Kirbys, falls in love with Alice Sycamore and brings his parents to dine at the Sycamore home on the wrong evening. The shock sustained by the Kirbys, who are invited to eat cheap food, shows Alice that marriage with Tony is out of the question. The Sycamores, however, though sympathetic to Alice, find it hard to realize her point of view.

Meantime, Tony, who knows the Sycamores are right and his own people wrong, will not give her up, and in the end Mr. Kirby is converted to the happy madness of the Sycamores, particularly since he happens in during a visit by an ex-Grand Duchess, earning her living as a waitress. No mention has as yet been made of the strange activities of certain members of the household engaged in the manufacture of fireworks; nor of the printing press set up in the parlor; nor of Rheba the maid and her friend Donald; nor of Grandpa's interview with the tax collector when he tells him he doesn't believe in the income tax.