 The negligent housewife Terry (Laura Dern) is married with the teacher Jack Linden (Mark Ruffalo) and they have a son and a daughter. The careful housewife Edith (Naomi Watts) is married with the teacher and aspirant writer Hank Evans (Peter Krause) and they have a daughter. The two middle-class couples are best friends, visiting frequently each other. Edith feels neglected by Hank, and has a torrid affair with Jack. Terry loves Jack, but cheats him with Hank. And life goes on.