A Link is formed out of fat from liposuction patients from a plastic surgery clinic. The link kills the plastic surgeon when he gets in the way of the link's food supply and then disappears into the Chicago water system. The first detective on the scene is Rich Talridge, who was O'Malley's first partner before Nick was picked for SU2. Rich doesn't like that the case has been handed over to SU2 and tries to solve it himself which gets him in trouble. Kate and Nick and the rest of SU2 are left trying to track and get rid of the "Fat Link" before it kills again.
