Booth meets with Neal's mother and brother who say he was fine when he was little. The parents says that Neal started to get hard to handle when he was fourteen. Neal's mom says she suggested he get his tail removed, but Neal wanted to keep it since he thought it was proof that he was the son of Satan. They say Neal ran away, implanted horns, then was put into the mental hospital.

Cam finds signs that Neal's intestine ruptured. After Arastoo removes Neal's shoe, Cam notices that it was infected with gangrene which is common for heroin junkies. On the body, Hodgins finds peat moss, sand, and perlite and Christmas roses which could be used in a ceremony to summon the Devil.

As they drive to the mental hospital, Booth wonders if Neal was possessed. Sweets says after he spoke to Neal's doctors, he found no sign that he was possessed. He explains that Neal had simple delusions.

At the hospital, Bones notices Christmas roses in the garden. The head doctor, Copeland, tells the team that Neal has went AWOL in the past. After the team asks him to speak to the patients, Copeland states that their mental states are fragile. Copeland says he didn't want to force Neal to remove his horns. Copeland introduces the team to a patient named Neviah who says God warned her that people would arrive with questions. Neviah shows them a picture of Neal on a cross and herself stabbing him with a spear. Copeland states that Neviah thinks that she is the angel Uriel. Bones points out that the wound that is shown in the picture is where Neal was struck.