Crain, Darnell, and Sothern star as three friends who, shortly before embarking on a Hudson River boat trip, each receive a letter from Holm (who's never shown), the fourth member in their set. The letter tells them that she has run off with one of their husbands but does not specify his identity. The women spend the rest of the trip reviewing their sometimes shaky unions which provides some of the funniest and most caustic scenes, including Douglas (as Sothern's husband) ranting against the advertising business which supports his wife's radio soap opera. Sharp dialogue, moving performances. Based on the novel by John Klempner. Remade for TV in 1985.