It's a normal case for the BAU. An unsub killed three women and is in a fast down spiral, the team is about to catch him. Things take a turn for the worse when Reid gets injured and wakes up in the hospital - and he knows nothing. Not even his name.

Six years ago, the BAU team watched their youngest member fall apart, and now as he grows secretive and distant again, they start to think the worse. Their suspicions get worse when they are called to Las Vegas to assist on a serial killer case and he closes himself off but when Dr. Spencer Reid disappears from his hotel room, the team have to work quickly to find him before they have another body on their hands.