Everyone in the BAU knows Spencer Reid and Y/N are in love. Everyone except Spencer Reid and Y/N. When the team is called to investigate a series of disappearances connected to an abandoned psychiatric hospital, the case seems straightforward—until Spencer and Y/N become trapped in the facility's underground tunnels with the unsub still hunting victims. Cut off from the team and running out of options, they must rely on each other to survive a deadly game of cat and mouse beneath the hospital. As the BAU races to find them, secrets are exposed, feelings become impossible to ignore, and the line between partner and something more begins to blur. Because escaping the tunnels may be the easy part. Admitting what they mean to each other might be harder.