When Liz and Red arrive at the Funny Farm to pay a visit to Dr. Sanders, a former researcher at the U.S. Army Medical Research Institute of Infectious Diseases, Red reminisces over this amazing scenario from only a few years earlier: "We spent a glorious weekend in God's country with two snow bunnies who were dead ringers for the Swiss Miss twins." Delightful, especially considering the cadaverous appearance of Dr. Sanders -- who could not have look much younger a mere two years ago, unless he contracted a rapid onset meth habit. Keen is also feeling rather irked by this comedy sketch. When Dr. Crazy starts talking about spacemen, she heads for the exit. As Red turns to follow her out, the doctor hands him some research. Keen has another meltdown in the hallway, accusing Red of luring her on this futile field trip just so he could plead his innocence. You're killin' me, Keen. Red admits that he does not know who Berlin is and he seems truly worried. But Keen is too busy kvetching to notice.
The Return of Scary Gary! Back at the Post Office, that bureaucratic henchman is chewing out Agent Cooper. Gary tells Cooper that with Keen's resignation in the works, Reddington will no longer have immunity. Gary's people will throw Red into a hole and never take him out -- no trial, no reconsideration, just gone. (Gary is working for some higher power other than the FBI, likely The Alliance, which we already know is embedded in the U.S. government.) Scary Gary also takes aim at Liz Keen, FBI Agent Extraordinaire: "I've gone on record with the director that we've been too indulgent with her. We've never fully surmised her relationship with Reddington and now her husband is a fugitive." That's fair. Then he lays it at Cooper's feet and says he'll get the axe too once this is over. Rude, Gary! The Feds really try their darndest, but things just don't always go as planned. Because this is really a high school rather than a federal intelligence agency, Malik and Ressler are heartbroken that Keen would leave them. "Is it true that you're leaving?" Malik says forlornly. "Don't be sorry, Liz. We'll support you no matter what you do," Ressler encourages. Aww, thanks, guys!
Turns out we need the crazy doctor. (When will Keen learn to simply trust Red on his people, even if she doesn't trust his motives? Crimony.) He has the formula for the pathogen, which means he must be working with the man infecting people. When Liz tells Red they need to make a second trip, he's reading the paper in the park, as if he was just counting down the minutes to when she'd come crawling back. Red pulls out a ziplock baggie with some pulpy red stuff in it and tosses it to Keen. It turns out to be Tom's message, the spider-tattooed neck skin from Red's tail -- which roughly translates to "Don't f--- with me."
Liz feels powerless, and unfortunately, she takes it out on the poor mental patient. She gives the befuddled old man the third degree; all he knows is that the contact is called UD4126. Then Liz has a revelation when she sees the nurse's badge, which has an identification number that could match UD4126. The handle matches a CDC agent named Nicholas Vogel. The FBI raids his house, find the virus and takes him into custody. Proceed with the questioning! This episode has a lot of questioning. Luckily, Liz gets better at it with practice.
NEXT: Lessons on blackmail