Why did Mandy the mermaid sit on the soft, white sand?

The other mermaids swam high in the bright blue water. They flicked their glittery tails. *Swish, swish.* They zoomed like fast fish. But not Mandy.

Mandy had a shiny purple tail. It was very heavy. When she tried to swim up, she sank down. *Plop!* She landed right back on the sand.

"Oh no," Mandy sighed. "I want to move and play."

Her best friend was Ollie the Octopus. He wiggled his eight orange arms. "I can help you, Mandy!" Ollie said with a big smile. "Hold on tight!"

Mandy held one sticky, wiggly arm. Ollie pulled hard.

First, they tried to swim to the sunny top.