Sheridan Whiteside, having dined at the home of the Stanleys, slips on their doorstep, breaking his hip. A tumultuous six weeks of confinement follow. The Stanley living room is monopolized by the irascible invalid; ex-convicts are invited to meals; and transatlantic calls bring a $784 phone bill. The arrival of strange gifts from his friends further destroys domestic tranquility. It would take a stoical housewife to harbor penguins in her library, an octopus in her cellar, and 10,000 cockroaches in her kitchen. When Maggie, his secretary, falls in love with the reporter, Bert Jefferson, Whiteside summons a glamorous actress, Lorraine, to win the affections of the young man. Knowing the girl's charms, Maggie enlists the aid of a clever impersonator who, affecting the voice of Lord Bottomley, whom the actress hopes to marry, asks her by phone to return to him and be married. The ruse almost works, but Whiteside, becoming suspicious, finds that no calls have come through from London. In revenge, Lorraine suggests a three-week rewrite on a play of Bert's in which she feigns great interest. Lake Placid is to furnish the quiet for his inspiration, and she is to be his collaborator. The unexpected arrival of a mummy case, just as the relenting Whiteside is frantically seeking to get rid of Lorraine, furnishes a malicious idea. Tricking her into stepping into the case, he shuts the lid and blackmails his host into having the case carried to the airport, preparatory to a round-the-world cruise. Whiteside departs from the Stanley's home triumphantly, but a second later a crash is heard—he has again slipped and fallen!