Cora hummed as she made a rock garden.
"What a beautiful day!" she thought.
"The reef is so calm."
Suddenly—bump!
"What was that?" Cora thought.
She swam toward the sound.
Mo was there too.
Many fish were swimming around a strange object.
"What is it?" Mo said.
Walt the turtle swam by. "Hmm.
Just a cement block.
Humans leave them for coral to grow on."
"More coral!" Mo said. "Cool!"
A fringehead pushed his way through.
The fish had a large mouth.
"That's mine!" he said in a bossy voice.
"I'll use it for my house."
"That fringehead is rude," Cora whispered.
Then another fringehead swam over.
"No, I want it! It's mine!" he said.
The two fringeheads opened their mouths wide.
A big, noisy battle began.
"Can you stop them, Cora?" a crab asked.
"They're so loud."
"They woke up my babies!" a fish said.
Cora swam to the fringeheads. "Please stop fighting.
You're upsetting everyone."
But the fringeheads didn't listen.
They just kept fighting!