Helen's life is ideal - her husband is an architect, a magnificent Victorian-style house, a friendly family and a long-awaited pregnancy, after many unsuccessful attempts. In happy anticipation, she enrolls in a pregnancy class in her area, where she meets Rachel - her polar opposite, loud, extravagant and lonely. For some reason, Rachel is terribly drawn to Helen, but soon the fledgling friendship begins to frighten her. It’s as if a new friend always happens to be nearby, unexpectedly comes to visit, knows, it seems, every little thing about Helen and her family. Events are developing rapidly, taking the most dangerous turns, and now it is no longer clear who is the criminal and who is the victim in a strange and confusing game.