David and Molly Jones, urban professionals, live happily with their toddler son Michael on Manhattan's Upper West Side. Then Diedre Grocci moves into their apartment building. She's David's moody ex-wife, and she wants him back.

Slowly, Diedre lures David back into a world of addictive, violent sex. David is hers for keeps now -- or so she thinks. But she doesn't reckon on David's wife. To hold on to her family, her sanity and her life, Molly will go to hell and back.