Susan and Ed Middleton are perfectly content with their lives. Two kids, two cars, a solid brick bungalow in a respectable beaches suburb. They're good people, model citizens. There's barely a ripple in the surface of their happy existence. But when Susan's older sister, who vanished as a teenager, reappears to claim an inheritance, everything is set to change... Karen – now known as Carly – has had a tough time during the past twenty years: drugs, prostitution, prison. At least that's what she tells them. As Carly insinuates herself further and further into the Middleton's lives, suspicions are aroused – is she really Susan's sister, returned from the dead? If she isn't Karen, who is she? And, imposter or not, why is the Middleton's relaxed and comfortable world suddenly spinning way out of control?