While driving his car, Homer hears strange thumping noises. He takes the car to a mechanic, who tells him that his car is fine, and that his heart is making that noise. Mr. Burns catches Homer eating donuts instead of working, calls him into his office and taunts him with threats of dismissal. When Burns tells him that he is fired, Homer's heart stops.

After learning that he has suffered a mild heart attack, Homer is told that he needs a $40,000 coronary bypass operation. Lacking tha money to pay for it, Homer tries to get health insurance. Just as he is about to sign the new policy, he suffers another heart attack and his application is rejected. Hearing a commercial featuring Dr. Nick Riviera, who will perform any operation for $129.95, Homer checks into the hospital, concluding that he has nothing to lose.

To brush up on the procedure, Dr. Riviera rents an instructional video. However, the most important part of the operation has been taped over. Homer says his final goodbyes to his family, just in case. An uncertain Dr. Riviera cuts into Homer and freezes. But Lisa, who has studied up on the operation, guides him through the surgery. Homer is soon back to his old self.