"Isn't it beautiful?" she heard her mother whisper. Her voice echoed. Lily could not see her in the dark. They were inside the mountain in a high, vaulted cavern washed hollow for thousands of years by the sea. Hundreds of tiny pinholes in the lava dome arching above them let in constellations of light. It was like the clear night sky. There were too many sparks to be stars alone: lightning bugs, thought Lily.
"Where are you?" she asked.
She felt the inky water move around her and then a hand splashed behind her and she found her mother's arm.
"Are you afraid?"
Lily didn't answer. She was always a little afraid in the Cave, no matter how many times she had been there. She could just make out the shape of her mother's round head next to her. There was the sound of wings beating. She kept looking around to make sure that the small, green circle of light, the opening to the world, was still beneath them in the water.
"It is really like being on the very edge of the planet," Anna said exultantly.
Lil's legs began to tire from treading water. The water was cold. She began to lose her senses. It became impossible to judge distances - the distance from her to Anna and the distance from minute to minute. It made her dizzy. the pull of the tide rocked them gently, just enough to make the mock stars above them change position. There was a story about two boys who had been caught in the Cave when the neap tide was coming in. They were unable to find their way out through the green hole in the rising water. Lily wondered what it must have been like, feeling yourself move higher and higher into the nigh sky. Their dead bodies were marked with hundreds of little pricks where they had been crushed against the lava.
Lily said, "I am getting tired, Mother."
Anna spoke as though she had been startled. "Oh, my old sweetheart."
Lily heard her other take in air, then the splash of her kick, then it was more silent than before. She floated on her back. She was alone in the Wet Cave. She turned over to watch the green light flicker off and on as Anna wiggled through the hole on her way back into the world, then she too dived into it and smiled as she felt the stream of warm, living sea slide over her.