An 8-year-old American boy wakes up alone in a rice paddy in a rural Chinese province with no idea how he got there. Details start to emerge when the boy, who calls himself Jacob (Landon Gimenez), recalls that his hometown is Arcadia, Missouri. Immigration agent J. Martin Bellamy (Omar Epps), call him Marty, takes him there.
The home the young boy claims as his own is occupied by a 60-year-old couple, Henry (Kurtwood Smith) and Lucille Langston (Frances Fisher), who lost their son, Jacob, more than 30 years ago. While they look different, young Jacob recognizes them as his parents. Lucille is overjoyed at the miracle of her son's reappearance. Henry, however, is reluctant to accept that Jacob is back.
Those closest to the family want answers, including Sheriff Fred Langston (Matt Craven), whose wife Barbara drowned 30 years ago while trying to save Jacob. He is shocked to see his nephew standing on his brother's porch. Jacob says hello to his Uncle Fred just before having some kind of seizure.
Jacob is rushed to the hospital where Fred's daughter, Maggie (Devin Kelley), a local doctor, examines him. The boy believes she looks like his Aunt Barbara. Jacob says he tried to help her at the river, but he fell in. He claims there was a man there holding Barbara's arm. Maggie asks the boy if he's afraid of someone. Elsewhere, a tough-looking man in a red baseball cap and a hoodie hitches a ride to Arcadia. He claims he has a boy there.
Pastor Tom Hale (Mark Hildreth) is stunned when Jacob mentions that he has the same name as his best friend. The boy wonders if he died. As for Tom, he knows in his heart this kid is his long gone friend from his youth. Still, even the pastor has trouble believing this possible miracle.
Maggie helps Marty dig into the files surrounding the incident at the river after having a private chat with her life-long friend, Elaine Richards (Samaire Armstrong). Barbara's autopsy photos show bruises that could indicate someone was holding her arm.
Jacob sneaks out of the hospital to revisit his old home. The man in the red cap and hoodie is also there. He's staring at the boy from afar when Henry arrives with Deputy Connor Cuesta, who is romantically involved with Maggie. Jacob takes off running. He's headed for the river. While running after him, Frank has a flashback to the days when he was a young dad playfully chasing after his son in the yard. When he and the deputy catch up with Jacob, he digs out an old G.I. Joe doll his dad gave to him.
Henry is having a lot of trouble accepting that Jacob is truly his son. He allows Marty to ask the boy about that day at the river. Jacob recalls seeing his cousin Maggie in a baby stroller. Then he heard his Aunt Barbara calling for help. She was hanging onto a branch trying to avoid being sucked into the river. Jacob tried to help, but fell in. He saw a man holding his aunt's arm before ultimately letting go. The man he saw is in a picture by the piano.
Marty gets a call. Test results prove that Jacob is, indeed, Henry and Lucille's son. Marty knows that his father believed the impossible when he saw his boy. That's not making this any easier. Pastor Tom speaks of miracles when Lucille walks into his service with Jacob by her side. He speaks of the price of human understanding and what it means to have faith.
Henry lets Fred know that Jacob said a man who worked for the company was at the accident. This person was having an affair with his deceased wife. At a bar, Elaine gets a call from her brother, Ray. He's talking crazy and has a gun. Marty joins her, Maggie and Deputy Cuesta as they head over to the house. Ray has someone trapped inside a shed. It's the man in the red baseball cap and hoodie. This mystery figure is Elaine's dad. It's obvious she hasn't seen him in a very, very long time.