Psychiatrist Walter Pinkham shoos dentist and office neighbor Myron Mandel from his office. The anxiety-stricken Myron is having self-esteem problems, believing his patients "shrink from his touch." Entering his own office, he mutters to his receptionist to get rid of the waiting patients by claiming he's sick. He sits down and begins breathing nitrous oxide. The receptionist calls the office depressing and promptly quits. He greets the patients then makes up a nonsensical story about retiring to do missionary work for Eskimos. Even more depressed after losing another batch of patients, he pulls an electrical cord from a piece of equipment and gets ready to hang himself. He's interrupted by Lydia Bixby, a patient he had found very attractive the day before and was looking for her hairbrush. With nothing left to lose, he asks her out, but she turns him down for exactly the reason he feared. He continues trying to hang himself, but the light fixture he threw the noose over breaks. He falls, but is caught by a burly man who identifies himself as the tooth fairy. Myron, believing himself crazy, doesn't take the man seriously. When the tooth fairy asks what he can do for Myron, he gets a laundry list of wanting patients to come to him willingly and respectfully, plus Lydia to fall madly, desperately, passionately in love with him. The tooth fairy calmly agrees. Myron asks for a miracle to prove it's not a hallucination. The tooth fairy tells him to look at Lydia's X-rays. As he looks, a filling falls out. Lydia returns, having lost her filling and suddenly amorous. He drills her tooth and they're soon locked in an embrace. The other patients return, desperately wanting him as their dentist.
Soon the waiting room is packed. Myron tells Dr. Pinkham that he's booked through the rest of the decade. He's tired and overworked. Lydia wants him to come home and make love to her. The patients argue amongst themselves as to who gets to go next. They break into a chorus of "For He's a Jolly Good Fellow," hoisting him on their shoulders. He slips away from them and runs for his life.
Myron catches a boxcar out of town. Inside are a group of hobos. He notices one of them using a dentist's mirror to eat beans from a can. When he identifies himself as a dentist, all of the other hobos follow. They all blame their plight on the tooth fairy, who gets more business when dentists aren't around to keep teeth from falling out. Myron is resigned to his new life.