It was early in the morning and still dark outside.
A garbage truck drove along West Street.
Suddenly bolts of electricity lit up the sky.
Za-wap! Za-wap!
A second later the sky was dark again.
"That was strange," said one garbageman.
"Yeah," said the other man.
"I wonder what . . . Oh no!"
Roar!
"I'm so glad it's Friday," said Jack.
"No school tomorrow!"
Roxy and her friends were walking to school.
Everyone was excited about the weekend.
"We should go to the park tomorrow," said Terrell.
"Great idea," said Roxy.
"Let's ride our bikes there."
"I'll bring a Frisbee," said Jack.
"We can play Frisbee tag."
Mara sighed. "I wish I could go with you," she said.
"But my parents made plans already.
They're taking me to the Metro City Natural History Museum."
"I love that museum," said Terrell.
"It has ancient fossils and cave paintings.
And lots of dinosaur bones!"
"Dinosaurs are awesome," said Jack.
"My favorite is T. rex."
Mara's eyes lit up.
"Hey! Why don't you all come with me?"
"Really?" said Roxy.
"Sure," said Mara. "My parents won't mind."
Roxy and her friends grinned.
"I can't wait!" said Jack.
"Maybe we'll see a T. rex skeleton!"
"I wish we could see real live dinosaurs," said Terrell.
"It's too bad they're extinct."
"You can see live dinosaurs, Terrell," said Roxy.
"You just need to invent a time machine."
"Ha-ha." Terrell pretended to laugh.
But then he looked excited.
"Hey! Maybe Rocket Girl could help us build a time machine!"
Roxy laughed and shook her head.
"Terrell, that's ridiculous.
I doubt Rocket Girl knows how to build a time machine."
Terrell sighed. "You're probably right."
Just then Roxy's watch beeped.
"Oh!" she said, looking at her friends.
"I just realized I . . . um . . . forgot my pencil box.
I'll see you at school!"
"Wait!" called Terrell as Roxy hurried away.
"You can borrow one of my pencils!"
But Roxy was already gone.
She went around the corner and made sure nobody was nearby.
She pressed a button on her watch.
Mayor Bloom's face appeared on the screen.
He looked nervous.
"Mayor Bloom, what's wrong?" asked Roxy.
"Metro City needs your help, Rocket Girl," said the mayor.
"Dinosaurs are roaming all over downtown Metro City!"
"But dinosaurs are extinct," said Roxy, confused.
"These dinosaurs aren't!" said the mayor.
"Now please, help!"
"Don't worry, Mayor," said Roxy. "I'm on my way!"