When Zack finds that Kelly is planning to go on a three-month cruise abroad for the summer, he desperately tries to cling on to her. He tries to make Screech drop out of traveling on the trip so he can take his place. But Zach eventually and makes a big choice to hold onto Kelly: he asks her to marry him. Meanwhile, Slater feels guilty when he sees another girl behind Alex's back since she shares the same interest as he, while Leslie finds out and tries to make him come clean with Alex about his dissatisfaction with their romance.