The gang enjoy the last class being taught by the beloved Professor Rich, who is about to leave on sabbatical. He is known and respected for his belief in living life to the fullest, and has traveled the world to that effect. Wanting one last chance to see him before he leaves for Cairo, they invite him to their dorm, where all of the students have planned a going away party. He arrives before Screech has returned with the cake, so Zack stalls him while the rest of the surprise party waits in the girls' room. To Zack's surprise, Professor Rich admits that he has been a fraud and that in reality he's done none of the the things he's become famous for, but that now with his trip to Cairo he wants to follow his doctrine of always living life to the fullest, and advises Zack to do the same. Zack returns to the others so that they can spring the surprise on their teacher, and everyone is stunned that in that brief moment Professor Rich has died.
As everyone prepares to go to Professor Rich's funeral, his death has had an obvious effect on Zack. Not wanting to make his teacher's mistakes, Zack now vows to live life to the fullest, and demands that Kelly admit to him whether or not she loves him. After some waffling, Kelly admits that she doesn't.
Between Professor Rich's death and Kelly's reaction, Zack reacts by taking his "live life to the fullest" attitude to the extreme. He buys a motorcycle, and scales the side of the Student Union. Then, after an off-the-cuff comment from Kelly, he decides to go sky diving. He even manages to convince Slater and Screech to go with him.
Right before the jump, Slater and Screech back out, but Zack still wants to do it. Until, that is, Kelly calls him from the tower. She admits that she loves him and wants to be with him, and Zack's dangerous actions suddenly seem very foolish to him. He also decides not to jump, but as the plane banks he, Slater, and Screech are thrown from the plane. After a moment's panic, they realize that they're enjoying the experience, but will never do it again. And once back on the ground, Zack and Kelly embrace and are obviously a couple once again.