Reid gets chased down by police in Mexico, and they find drugs and money in his car's trunk. He's lost his memory. His hand is all cut up. He's in Mexico to meet a woman named Rosa Medina. He's being held for drug possession with intent to distribute. The BAU flies to Mexico to help him. Their theory is he went to Mexico, where he has been three times recently, to find alternative medicine for his mother's Alzheimer's. The team is guessing Mr. Scratch is behind Reid's predicament. Walker figures out that Rosa is actually Nadie Ramos, a doctor who is studying brain degeneration. She's found dead in her hotel room, stabbed 25 times. Reid was given a speedball, a combination of cocaine and heroin, which is causing his memory loss. Prentiss gives Reid a cognitive interview. Reid recalls he was meeting with Rosa with someone broke into her hotel room and stabbed her, and he cut his hand trying to defend her. The Mexican authorities charge Reid with murder. Clara Seger and Matt Simmons from the International Response Team arrive to help. Reid is being transferred to a maximum-security prison, even though the team discovers that Rosa had dual citizenship, which should get Reid extradited back to the U.S. His transfer is stopped, and Reid is expedited back. He still has to be jailed as a murder suspect, and the FBI won't give him legal help, since he was in Mexico unofficially.