Matthew (Ryan Reynolds) and Tina (Mireille Enos) are a couple who have been married for many years. They have raised a lovely daughter, Cassandra (Peyton Kennedy), and the family of three lives in happiness and happiness. One day, Matthew drove Cassandra home. This was an ordinary day, but it became a permanent nightmare for Matthew's family. Matthew left Cassandra in the car to buy dinner by himself. When he returned to the car, he found that Cassandra was missing. Cassandra disappeared, and Matthew's family and marriage were on the verge of breaking. Tina has never been able to forgive Matthew's negligence, and Matthew has been living in self-blame every day. In a blink of an eye, many years have passed, and when the pain of the past has been gradually covered by time, a photo of Cassandra appeared on the Internet.