M (Rooney Mara) and C (Casey Affleck) are a pair of very loving lovers. In a car accident, C unfortunately died, leaving the heartbroken M alone in this world. However, C did not really leave. He still stayed in the house where he and M lived together in the form of a soul, staying by M's side, silently and affectionately watching every move of his former lover. C's departure made M fall into despair and pain. She cried, depressed, and autistic, as if living in a vacuum. M decided to move out of the house, but C could not leave. He could only continue to wait and wait. What supported C was a note that M had left in the cracks of the wall. New residents came and went, and infinite time passed forever. One day, the demolition team demolished the house where C was. In the ruins, C discovered that he was not the only one trapped in endless waiting.