Traffic filled the streets in downtown Metro City.
"Whoa," Roxy thought. "The roller-skating party is causing a big problem!"
Detective Smith stood near his car. Dance music played loudly over huge speakers.
Roxy smiled. "Cool party, huh, Detective?"
"What?" Detective Smith said.
"I said, 'Cool party,'" Roxy said.
"What?" The detective held a hand to his ear. "I can't hear you over this loud music!"
Roxy laughed. "Never mind."
Detective Smith made a funny face. "What?"
At recess kids were dancing and looking at a phone. Mara, Jack, and Terrell went over to them.
"What are you watching?" Mara asked.
"A roller-skating dance party," someone said. "It's being livestreamed on Cooltube!"
In the video a group of people skated and danced. Dance music played loudly.
One skater appeared on-screen. "Hey, everyone. I'm Derby Wheels. And we're the Wicked Wheels Gang—Metro City's number one roller-skating club. Woo-hoo!"
Derby zoomed past speakers and a DJ booth. "Big shout-out to my brother DJ Wheels! He keeps the music going! Yeah!"
DJ Wheels pumped his fist to the beat of the music.
Mara started to dance. Terrell and Jack did too.
A man stomped into the video's background. "Get out of the street! You're blocking traffic!"
Derby laughed as she skated past him. "Stop yelling, mister. You're ruining the party!"
Other skaters danced around the man. He sighed and walked away.
The kids laughed. But then someone else appeared in the video.
Jack gasped. "Rocket Girl!"
Roxy landed near Derby Wheels.
Derby skated around her. "Hey, Rocket Girl! Where are your skates?"
Roxy folded her arms. "I'm not here to roller-skate. You need to go somewhere else. Your roller-skating party is over."
"Boo!" Derby said. "This party never ends!"
Derby skated away. She was still dancing and having fun.
Roxy flew after her. "I'm serious, Derby! You all need to stop this party right now!"
Jack scratched his head. "Why is Rocket Girl trying to stop the party? I thought she was cool!"
"Yeah," a boy said. "Those skaters are just having fun."
Terrell shrugged. "Their party is blocking traffic. Maybe that's why Rocket Girl is trying to stop it."
Roxy flew over to the DJ booth. "Turn off the music!"
DJ Wheels made the music louder.
Roxy stamped her foot. "Turn it off!"
"Boom," DJ Wheels said.
Roxy frowned. "Boom?"
"Boom." DJ Wheels pressed a button. A missile shot from the booth and hit a parked car. Boom!