"I must get to the construction site," Roxy thought.
"I have to find out what's causing the sinkholes!"
She called over to her friends.
"Hey, guys! I'll be back.
I, um, forgot my shin guards!"
She hurried away from the soccer field.
"But you don't need them!" Terrell called after her.
"We're not having soccer practice!"
Roxy was already gone.
A second later Rocket Girl flashed through the sky.
"Look!" cried Mara. "It's Rocket Girl!"
Roxy flew over Metro City.
She saw large holes everywhere.
They looked like giant gopher holes.
She spotted Detective Smith at the construction site.
He was talking to two workers.
Nearby stood a building that wasn't yet finished.
The entire site was filled with large holes.
Roxy landed next to the detective.
"What's going on here, Detective?" she asked with a grin.
"Are you digging for treasure?"
Detective Smith frowned.
"That's not funny, Rocket Girl. Something very strange is happening in Metro City."
"I know," said Roxy. "Big sinkholes are everywhere.
Does anyone know what caused them?"
"We have no idea," said the detective.
"But we need to find out right away.
Things are disappearing into the holes!"
"All the vehicles from this construction site are missing, right?" said Roxy.
"Yep," said one of the workers.
"Every dump truck, crane, and bulldozer!"
"My car is gone too," said the other worker.
She looked frightened.
"It just sank into the ground!" She pointed to a big hole nearby.
"Did you see it happen?" asked Detective Smith.
The worker nodded. "First there was a loud rumble.
The ground shook. It felt like a small earthquake.
Then the hole appeared, and my car sank right into it!"
Suddenly—rumble, rumble! The ground shook violently.
"Oh no!" cried Detective Smith. "It's an earthquake!"
The building wobbled. A big piece of steel fell from it.
"Look out!" Roxy cried.
Detective Smith and the workers ran out of the way.
Roxy flew up and caught the piece of steel.
"Whew!" she said as she laid it safely on the ground.
"Rocket Girl!" Detective Smith called over the loud rumble.
"What do you think is causing this earthquake?"
"I don't know!" Roxy called back.
"But we need to find out . . ."
Roxy stopped talking.
Her super ears were picking up a new sound.
Beneath the loud rumble, she heard something very surprising—voices!