In a quiet London suburb, a group of mothers relies on each other for friendship, favors and gossip. But some of them shouldn't be trusted, and others have dark secrets.

When Callie moved into her new neighborhood, she thought it would be easy to fit in. The other parents have been strangely hostile, though, and her frail daughter, Rae, is finding it impossible to make friends. Suzy, with her rich husband and her three energetic children, has been the only one to reach out, although their friendship has recently felt inexplicable strained.

Now the police have suggested that someone dangerous might be living in their neighborhood, and the atmosphere feels even more toxic. Then there's the matter of Callie's ex-husband, and the shocking truth behind their divorce...a truth that she would do anything to hide.