Lynne and Howard Harper are finally about to make their dream of a six-month sailing trip in the Caribbean come true. But then something happens, the atmosphere grows tense, and the journey threatens to go up in smoke. Lynne’s sister Ann-Margret offers to house-sit... Lynne is perplexed by Howard’s behavior. He avoids her, always has something to do and there’s no sex either. When he suddenly has to go back to New York, he forgets his cell phone: but Lynne has heard enough... Who is the young woman who keeps answering? For Ann-Margret privacy doesn’t exist, so she advises her sister to check this out. Lynne discovers suspicious withdrawals for an apartment in New York made from Howard’s bank account. The sisters have it all figured out; Howard must have a lover. Lynne then infiltrates the communal apartment in which the young Samantha lives. And when Lynne discovers that the travel funds are missing, she rashly sells the boat. All hell is loose now, and only Ann-Margret seems to be on top of everything.