Headed by Grandpa Vanderhof, the Sycamores of Manhattan are a completely uninhibited family of lunatics whose members simultaneously manufacture fireworks in the basement, distribute left-wing propaganda in homemade candy, practice ballet in the living room, hunt snakes, play the xylophone, attend commencement ceremonies, operate amateur printing presses, and turn out play after play on a typewriter that was delivered to their home by mistake.

One exception to this wildly unconventional family group is Alice, the single “normal” member of the Sycamore family. When Alice and her conservative, wealthy boyfriend Tony become engaged, their families meet for dinner where the only thing louder than the fireworks exploding in the basement is the laughter roaring from the audience.