Strange things start to happen to sixteen-year-old Haley after she notices the Watcher. He looks like an ordinary teen, but his gaze is menacing as he observes her and her family at a restaurant. And then he's gone-vanished-leaving behind a pair of shimmering silver sunglasses. When Haley peers through the sunglasses, colors fade and her best friend becomes someone else. Freaked out, she vows never to use the glasses again. But the Watcher returns with deadly intentions. And after Haley is in a near-fatal car crash, she realizes the sunglasses are her only hope to prevent a murder. She slips on the glasses and enters a parallel world where dead people live and beloved friends die. To survive in this duplicate world, Haley plays out the ultimate masquerade-pretending to be the girl living a twisted version of her life: her parallel twin, Halee.