When they were children, Darby McCormick, Melanie Cruz and Stacey Stephens were friends. One night in the woods, drinking beers to celebrate Melanie's sixteenth birthday, the three teenagers become witnesses to a grisly scene - a woman is strangled to death. Darby and her friends escape and the killer plots revenge. This time, only Darby survives. Twenty-five years later, Darby is a crime scene investigator for the Boston Police Department. When a young woman is abducted from her home in the middle of the night, Darby finds an unexpected witness - a woman dressed in rags hiding behind garbage cans underneath a porch. The woman has been nearly starved to death, and is so distraught, so terrified, she believes she is still locked inside a dark prison cell - and that Darby is one of her fellow prisoners. Darby's investigation reveals that the woman, Rachel Swanson, has been missing for more than five years. And there are others. As Darby tries to get Rachel Swanson to talk about the missing women and the horrors she endured, the killer known as Traveler emerges from the shadows. As the race to find the killer heats up, Darby finds herself trying to unravel clues about the case while trying to uncover the existence of a killer who has eluded the police and FBI for over two decades - a killer who will use every means necessary to protect himself and to keep the missing women from ever being found . . .