Passengers from four vehicles rush to the scene of an accident after a fast-moving car sails off the edge of a mountain road and tumbles down a steep embankment. They include J. Russell Finch, president of the Pacific Edible Seaweed Company, who is traveling with his wife, Emmeline, and his shrewish mother-in-law, Mrs. Marcus; dentist Melville Crump and his wife, Monica; gag-writers Benjy Benjamin and Ding Bell; and furniture mover Lennie Pike. The victim, Smiler Grogan, reveals with his dying breath that he has buried $350,000 in stolen money under the "Big W" at Santa Rosita Beach State Park. Unable to determine the identity of the "Big W" or even to decide on a way to divide the cash, the greedy witnesses disperse and head for the park. Along the way, the Finch party takes on Englishman J. Algernon Hawthorne and Mrs. Marcus' beatnik son, Sylvester, and is forced to tell them of the money. The Crumps charter a dilapidated plane to give themselves a time advantage but are later delayed when they are accidentally locked in a department store basement and forced to set off an explosion to free themselves. Benjy and Ding ask drunken millionaire Tyler Fitzgerald to fly them to the site in his private plane, but he accidentally knocks himself unconscious in the cabin, and the two writers are forced to crash-land in an airport restaurant. Lennie, who has demolished a service station in his zeal to reach the park, is forced to take traveling salesman Otto Meyer into his confidence and later swears revenge when Meyer leaves him stranded on the road. Meanwhile, state police captain C. G. Culpeper, who has pursued Grogan for years, is having everyone carefully watched, patiently waiting for them to lead him to the hiding place; the captain, plagued by an unhappy family life and an inadequate pension plan, has decided to steal the money himself. The group, since joined by two taxi drivers, eventually discover four palm trees growing in the shape of a "W," and they uncover the money. Culpeper moves in to arrest the group and then tries to escape with the suitcase full of money. The men in the group pursue him in the two taxis and end up on the top of a fire escape of a condemned building where, in the confusion, the suitcase opens and scatters money to the crowd of spectators below. The fire escape comes unhinged and the fire department tries to rescue the men with a ladder truck, but the ladder topples when everyone climbs on simultaneously. The men are thrown to the ground, and all end up in the hospital--badly injured and under custody, with bankruptcy and prison sentences awaiting them. Culpeper is wondering if he will ever be able to laugh again when the despised Mrs. Marcus enters the corridor and slips on a banana peel. The downtrodden men burst into uncontrollable laughter.