The gang is forced to choose between supporting Kelly's relationship with Jeff and helping Zack cope with his grief over their break up, while Lisa plans her sweet sixteen party.

After Mr. Belding accidentally bumps into Zack before a big basketball game and injures his knee, he gets rushed to the hospital and gets told by Lisa's mother that he has to have surgery to repair the damage. As a result, Zack gets scared and tries to sneak out before going under the knife.