Ben, Gwen and Grandpa Max go to a mini-golf course that looks like a miniature town, but are soon interrupted by the Ground Hawg Gang. The gang, thinking that the course is a real town, try to destroy it!
The episode starts off with a glimpse of the future - Gwen telling Ben to look behind him as a member of the Ground Hawg Gang leader pulls up behind him. He then looks around questioning how things got so bad. Flash back to the present, the Tennysons arrive at a mini golf course, and Ben doesn't want to be there. Ben questions who wants mini things when they can go big, but Max explains that bigger isn't better. Ben claims that mini golf is too easy, so Max lets him take a swing. Ben doesn't hit the ball properly with the golf club, so he transforms into Diamondhead to hit the gold ball. He then cheats by pushing the ball into the hole. He then celebrates by jumping up and down. Suddenly, an earthquake occurs. Ben protects Sally and Todd from a falling object that almost hurts them. However, they both complain. Right after, the Ground Hawg Gang ride their bikes from beneath the ground. They reek havoc on the golf course. Right as Diamondhead prepares to attack, Ben times out.
Gwen and Max await at the beginning of the course, and Gwen mad at the groundhogs for ruining a good game. Meanwhile, Ben continues to run from the gang. He jumps in a river to stay safe. He then spots the word AniMotors on their bikes, figuring out that they were created by Dr. Animo. Max and Gwen helps Ben out of the water, and Max tells Ben to be careful. Ben walks over to the groundhogs, and attempts to transform into Wildvine. However, he gets Upgrade. He manages to take over one of their bikes, and is chased down by the whole gang. He manages to get their bikes destroyed, except for the leader. Gwen notices all of the damage that is being caused, and yells to get Ben to dial it back. Ben soon times out, and is in the situation shown in the beginning of the episode. Gwen telling Ben to look behind him as a member of the Ground Hawg Gang leader drives behind him.
The leader claims that he and his gang will ride town after town, and destroy them all, and Ben can stop him. Ben's watch times in, and he transforms into Grey Matter gets him to chase him as has a plan. He runs into a miniature house, hoping that the leader overshoots the turn. However, he does not. So Grey Matter is chased around even more. The Groundhog crashes his bike, destroying it. He runs to the "winner" obstacle, forcing the Ground Hawg leader to follow him in there. It's a dead in, but Grey Matter uses the electricity to defeat the boss. Grey Matter falls out, and is cornered by the rest of the gang. They then make him the new boss, as he defeated the old boss. They await their next commands. Ben makes them fix the mini golf course. Afterwards, he demands them to attack Dr. Animo. Gwen questions if letting them go was a bad idea. Ben denies it, and claims it's Animo's problem now. Max claims that the mutant biker gang remind him of his twenties. Both Ben and Gwen are surprised at the fact that Max was in a biker gang.
It is revealed that Max used to be in a biker gang in his 20's.