Jimmy is standing in the boxing ring over the knocked out Bif, gloating and telling the Preppies he's better than they are. Derby Harrington, the leader of the Preppies clique, comes down from the bar on the second floor of the gym to find out what the noise is. Parker fills him in on what just happened - Jimmy beat Bif and became the new Champion.
Derby, however, won't accept this. He sics the Preppies on Jimmy and runs back to the bar.
Jimmy first has to fight past Bryce and Gord outside the boxing ring, and then past Chad in the second floor hallway or get past Justin who is in the other way where Jimmy went to begin "The Eggs". He forces his way into the bar room, where Derby is hiding behind the bar.
Derby's main strategy is to continually call the other Preppies into the room to help him. Any of the other preppies except Bif, Tad and Pinky may appear in the room, and they come in twos. They also have smaller life bars than normal and can be beaten easily.
Whenever Jimmy knocks out the other two preppies, Derby knocks him out with an uppercut and jumps behind the bar to call in more backup. Jimmy cannot shoot Derby with his slingshot while he's behind the bar. He also cannot leave the bar even when the Preps rush through the doors due to an invisible barricade.
The two doors leading into the bar can both be blocked off. Once Derby can't summon more help, he quits hiding and fights Jimmy straight up. He can still be a bit of a challenge as he has excellent defenses, usually blocks grab attempts, and has an attack that goes through Jimmy's guard. He is, however, not completely immune to grapples and it is possible to perform the knee drop on him during this fight.
Jimmy can also attempt to ignore Derby's help and focus just on him, but this can make the fight very difficult. An ironic strategy is for Jimmy to repeatedly throw the other Preppies into Derby - this damages him without damaging them, and so he'll never retreat.
The mission ends with Jimmy forcing Derby to say that he's in charge.
- Derby is the only boss to have his name above his life bar entirely in capital letters. There doesn't seem to be any reason behind this, and is probably just a small stylistic oversight by the developers.
- Derby appears in Complete Mayhem in Chapter 5, and is a lot tougher than what he was in this mission. He uses Bif's fighting style and has a much bigger life bar in that mission, but he has better blocks in this mission.
- If you humiliate Justin and he runs into the bar, the fight will begin and Justin will be standing up and can be passed through.