“How can you have the same cousin?” Raymond was confused. “I didn’t even think you were related.”

“It’s through marriage,” Hailey said because she’d heard other people use that excuse to explain complicated family relationships.

“And divorce,” Claire added, because she’d heard that as well.

“Anyway, she’s a very distant cousin,” Hailey said. “We just want her to have a good time while she’s here. All you have to do is show up in the cafeteria at six o’clock tomorrow night.”

After Raymond had agreed to the dinner, Claire began to wonder how Hailey kept coming up with all these ideas, one after another, as if they just popped into her head. Now, for instance, Hailey raced to the pool, where she sat with her feet dangling in the shallow end. She took a can of tuna and an opener from her backpack, having remembered that the mermaid would be hungry.

“Good thinking,” Claire said to her friend.

Claire sat beside Hailey, but was careful not to hang her feet over the edge of the pool. She looked into the water, and gingerly dipped one toe in. It wasn’t quite as cold as they’d thought it might be. Just to be safe, she held on to the concrete.

When they told Aquamarine of her date with Raymond, she let out a shriek of joy that chased the perching seagulls into the sky.

“You only have to promise one thing,” the girls reminded her. “After tomorrow, you’ll go.”

Aquamarine begged and cried until the pool was awash with blue tears which stained the moon jellyfish turquoise and indigo, but the girls would not change their minds.

“We’re doing this for your own good,” they said. “We want what’s best for you.”

Without saltwater, they told her, Aquamarine’s skin would soon dry up until her fresh face became grainy as sand, her beautiful pale hair would curl like seaweed, her tail would turn limp and dull. Already, her time away from the ocean had caused her to fade, so that when she blushed or was angry she turned silver rather than blue. The webbing between her fingers had fallen away, and her hands looked like those of any ordinary girl. Out in the waves, her six sisters were calling for her. They missed her and worried and at high tide they came dangerously close to shore in their search.

“All right,” Aquamarine said finally. “I promise I’ll go.”

Upon making this vow, the mermaid cried even harder.

“Cheer up,” Claire said. “You’ll always remember the night you had together.”

But now that Aquamarine was to get her heart’s desire, she was nervous. “What if he doesn’t like me?” she wondered.