Roxy kept listening to the underground sounds.
"I hear the ground shaking," she thought.
"And something that sounds like a big machine underground.
Plus those voices again.
Where are they coming from?"
Roxy looked at Detective Smith and the construction workers.
"Everyone, stand back!" she said.
Roxy started to spin like a top.
A hole formed under her feet.
Pieces of blacktop flew everywhere.
She went faster and faster, drilling into the ground at super speed.
"Rocket Girl!" called Detective Smith.
"What are you doing?"
But Roxy didn't answer.
She was already deep underground.
Roxy arrived in a huge dark cave.
"Look! A human!" shouted a voice over the loud rumble.
Using her super vision to see in the dark, Roxy spotted several tiny men.
They had mole-like faces and wore brown jumpsuits.
The men stood next to a big machine.
It looked like it was built out of truck parts and other construction equipment.
"Who are you?" Roxy demanded.
One of the men pulled a lever, and the machine stopped running.
"We're the mole men!" he said.
"And we're going to destroy Metro City!"
Roxy gulped. "Why do you want to do that?"
The mole man glared at Roxy.
"We're sick of humans digging sewers and subways down here.
The underground is for mole men only!"
He looked at the other mole men. "Grab her!"
Two mole men ran toward Roxy, swinging iron pipes at her.
Roxy jumped out of the way.
The mole men crashed into the cave wall.
"Ouch!" one cried.
Whap! The other one swung his pipe.
"Ouch!" the first one cried again.
"Oops!" said the other.
The two mole men looked around.
"Where did she go?" they asked.
"These mole men don't see very well," Roxy thought. "Just like real moles!"
"There she is!" One mole man pointed at Roxy. "Get her!"
More mole men ran toward Roxy.
"No humans underground!" shouted one mole man.
"The underground is for mole men only!" shouted a second mole man.
Again Roxy jumped out of the way.
All the mole men bumped into one another.
They tripped and crashed into the wall.
One mole man was still near the earthquake machine.
He pulled the lever, and the machine rumbled loudly.
Zap! A ray shot from the machine.
It blasted the ceiling of the cave, and big rocks crashed down onto Roxy!