In Los Angeles, three women have been found murdered in three separate incidents. Each was knocked out by chloroform without a chloroform burn outside their nostril or mouth, drowned in methanol where they were submerged alive, dumped in a highly public place, and had a two-inch square piece of skin removed from the bottom of their right foot, the skin removed post mortem. The dump sites and the abduction sites span the entire breadth of the city. The BAU believe that the unsub is a highly anti-social man, has some sort of scientific background, and is able to move around the city easily without attracting attention especially in interacting with or abducting the women. They narrow in on taxi drivers, but because no licensed cab was within the vicinity of the time and area of one of the abductions, they believe the unsub drives an unlicensed cab. The chemicals used in the murders may provide the missing piece in zeroing in on the unsub. During this investigation, Morgan notices that Prentiss is not herself. That is indeed the situation, but she asks that he trust her not to dig any further into the issue.