Marta was nervous. Shelley had invited her to go to her lake house for the weekend. Mom and Dad had said yes! But a lake meant swimming, and Marta had never gone swimming before.

The car pulled up to the house. Marta thought it looked beautiful. There was a big porch with flowers in front. There were lots of green, leafy trees. And there, in the distance, Marta could see the lake.

Shelley jumped out of the car. “Come on, Marta!” she called. She ran upstairs with her backpack. She opened it and took out a swimsuit. “First swim of the weekend!”

Marta followed her slowly. She unzipped her bag. She took out the green swimsuit that Mom had bought her only yesterday. She thought maybe she could just bob around holding on to the pier. That way Shelley wouldn’t notice that she couldn’t swim.

Shelley flew down the stairs in her pink suit. Marta plodded down after her in her green one. She was sure that every other 4th grader on the planet knew how to swim. It was so embarrassing.

At the lake Shelley walked out to the end of the pier. Marta followed. Shelley jumped in with a giant splash. “Wheee!” She flipped onto her back and floated. Then she dove deep and shot up out of the water.

“Come in, Marta!” Shelley called. “It’s so refreshing!”

Marta dipped her toe in the water. She couldn’t delay any longer. She sat on the edge of the pier and dangled her legs in. And that’s when she noticed it. Something was shimmering on her ankle.

 Marta bent down to take a closer look. The shimmery stuff was spreading. As they crept up her leg she could see they were scales! They were green and sparkly in the sunshine. What was happening?!

Marta lowered herself into the water. The scales spread higher. They stopped when they reached her waist. She looked down. Through the clear lake water she could see it. A beautiful, green, mermaid tail!

“Shelley!” Marta screamed. “Look!”

Shelley swam over to see. “Oh my goodness, Marta!” she exclaimed. “Why didn’t you tell me you were a mermaid, too?”

“Too?” asked Marta. She looked down at Shelley’s legs. Sure enough, below her waist was a shimmering, pink tail.

“Let’s go!” said Shelley. She swam off towards the center of the lake. Marta followed. To her surprise, her tail made it easy for her to swim. It felt amazing!

“Where are we going?” she called.

“The mermaid grotto,” Shelley answered. “You’re going to love it!”