Rachel, whose life has spiraled into depression and alcoholism, becomes intrigued by a couple she dubs Jess and Jason who she spots from her commuter train every day. One day as she is passing their home, she sees Jess kissing a man who is not her husband. Shortly after, Jess disappears entirely. Told from the intersecting perspectives of Rachel, Jess and Anna, Jess’s neighbor, an intriguing thriller unfolds. But who is telling the truth?