In a film based on Neil Simon's hit play, Walter Matthau portrays three unconnected roles. Sam Nash reluctantly joins his wife, Karen (Maureen Stapleton), in the suite where they spent their honeymoon, hoping to revive their flagging marriage. Then Jesse Kiplinger, an aging movie producer, is determined to seduce his old flame, Muriel (Barbara Harris). Finally, Matthau is beleaguered father Roy Hubley who, with his wife, Norma (Lee Grant), struggles to get their daughter to her own wedding.