Will (Leslie Odom, Jr.) and Eva (Freida Pinto) seem destined for a storybook life together, but their world is suddenly disrupted when Eva’s roommate, Carolyn (Tia Hendricks), bursts through the door and collapses. As ash falls from the sky, Will completes a chaotic trip to the hospital, realizing quickly what is happening. With Eva covered in a hazmat suit, he rushes her home and seals the windows and doors. Weeks become months become years and, after Eva makes a desperate move, the couple is forced to run for their lives. Only is a mysterious, dreamy post-apocalyptic love story, where Eva and Will attempt to survive in a new world where she is a commodity of unparalleled worth.