When a girlfriend's mononucleosis requires them to forgo sex, George discovers that his intellect is on the rise. And while happy to be dating a doctor, Elaine is surprised to learn that he hasn't passed his licensing exams. Then, after his agent books him at a junior high school career day, Jerry is bumped by a speaker from the zoo. Invited back to try again, his talk is then interrupted by a fire drill. Meanwhile, Kramer opens a smoking lounge in his apartment.
When a restaurant patron needs emergency medical attention, Ben proves to be of no help at all. So, to help him pass his exam, Elaine suggests giving up sex, only to find that, for her, celibacy has exactly the opposite affect as it does on George. Meanwhile, when Katie books Jerry for two hours at the junior high, George offers to help dazzle the students with a display of his amazing intellect. And when the diagnosis proves to be wrong, he also resumes relations with the sex-starved Louise.
As Kramer begins suffering the ill-effects of tobacco smoke, lawyer Jackie Chiles prepares to launch a big liability lawsuit. However, while Jackie hopes to use his client's wizened face to bolster their case, Kramer settles for an offer to model in the tobacco company's new ad campaign. Meanwhile, as Elaine looks for sex in order to clear her head, Ben passes his exam and decides to find someone better. And when sex with Louise renders George helpless, he costs Jerry an appearance on a popular TV show.