The family of Martin Vanderhof lives "just around the corner from Columbia University—but don't go looking for it." Grandpa, as Martin is more commonly known, is the paterfamilias of a large and extended family: His daughter, Penny, who fancies herself a romance novelist; her husband, Paul, an amateur fireworks expert; their daughter, Alice, an attractive and loving girl who is still embarrassed by her family's eccentricities—which include a xylophone player/leftist leaflet printer, an untalented ballerina, a working couple on relief, and ballet master exiled from Soviet Russia. When Alice falls for her boss, Tony, a handsome scion of Wall Street, she fears that their two families—so unlike in manner, politics, and finances—will never come together.

During a disastrous dinner party, Alice's worst fears are confirmed. Her prospective in-laws are humiliated in a party game, fireworks explode in the basement, and the house is raided by the FBI. Frustrated and upset, Alice intends to run away to the country, until Grandpa and Co.—playing the role of Cupid—manage not only to bring the happy couple together but to set Tony's father straight about the true priorities in life. After all, why be obsessed by money? You can't take it with you...