A 10-year-old, Adrian, disappears from a playground, leaving his mother distraught. Now 25 and suffering from agoraphobia, Adrian hasn't left his home in 15 years, with the truth of his abduction left lingering unresolved. However, his sheltered life starts changing when his brother Barton, with the help of the ominous Dr. Mountebank, enacts a radical new therapy to force him out. Further complicating things, Adrian's new neighbor, Raziela, brazenly inserts herself into his life, walking through his "locked" front door unannounced and distracting from the first sign that something is amiss. Adrian then begins experiencing horrifying nightmares revealing his abduction, where he was held in an old, dirt-floor basement. During his waking hours, he starts finding rooms mysteriously devoid of his stacks of newspapers and books that once lined every wall, only for Barton to take responsibility. Feeling betrayed, Adrian confides in Raziela, who is having fun forcing him out of his comfort zone. As Adrian's nightmares worsen, he relives his mother and father taking their own lives, but Barton becomes unreachable, leaving him to tell Raziela, who reveals that his brother isn't real. In disbelief, Adrian grabs a photo that is now missing Barton before running to his brother's bedroom, only to find it empty. As his sanity slips away, Dr. Mountebank stops by, reinforcing Barton's fictional status and causing Adrian to lash out with a baseball bat. The doctor touches the bat, causing it to turn to ash before Adrian passes out. In another nightmare, Adrian is held down to his bed by several masked men who flay the flesh from his body. As the pain becomes unbearable, the masked men disappear, replaced by Raziela, who shoves a knife through his skull. Adrian wakes up, convinced the dream was real, only to push Raziela away. Dr. Mountebank then tells a very real Barton to finish things, which finds Adrian in a nightmare where he is ten years old, locked in the basement with his captor, Travis. As Travis is about to hurt him, Adrian attacks, killing him. Adrian awakes to a masked man holding a knife to Raziela's throat, which he promptly slits before disappearing into the basement. Having had enough, Adrian attempts to leave the house, only for walls to appear, closing everything except the basement. Out of options, Adrian descends the stairs, finding the same dirt-floor basement from his childhood. A masked man then emerges from the darkness, revealing himself to be Travis. As Adrian's sanity breaks, Travis becomes a demon, promising it's all real before subjecting him to one final punishment. Beaten and bloodied, Adrian emerges from the basement, the door to the house wide open. Stumbling into the street, he finds Barton waiting to greet him. Barton reveals that Adrian is, in fact, Travis, and he is in hell, being forced to live out the tortured lives of all 15 of his victims. Since Adrian was the 15th victim, Travis must return to the first victim, where the cycle starts again.
