Criminal Minds S15 E10 And in the End (2)

"To catch a criminal, you have to think like one."

Following an explosive face-to-face encounter with Everett Lynch, a.k.a. “The Chameleon,” Dr. Reid suffers from a brain injury and, while experiencing hallucinations, is visited by ghosts from his past. Also, the BAU makes a shocking discovery about Lynch that affects Rossi personally, and the entire BAU team comes together to celebrate Rossi’s retirement.