Lucy’s tentative promise nestled deep in his heart.

Even more important than when she had accepted his Sea Opal, her promise to join him forever etched the stone of their fate. She knew what his ocean world truly entailed. She promised to leave the air world behind.

“Come. We will go to my city.”

She wiggled. “Let me grab my cell phone. How deep is your city?”

“It is on the bottom of the ocean.”

“The bottom close to an atoll like this, or the bottom of a trench?”

“We are not near a trench. However, swimming directly up to the surface would take a long, long time.”

“Probably deeper than the waterproof case is rated for.” She relaxed into him. “I’ll come back. We’ll organize deep sea cameras later to take pictures of a real mer city.”

“You will have many chances.”

He heard her unspoken doubt. I hope so.

“You will.”

She smiled.

He twirled with her through the water. His body pulsed to take her now, and fulfill their ancient destiny in this submerged church. She shone within his arms, nearly blinding.

But her doubts remained. She feared she could not give him young fry. She needed to feel the healing song of the Life Tree to chase her last fears away.

He led her to the cave entrance.

She kicked furiously to keep up. “I can’t make my feet into fins like yours.”

“You must flex.” He demonstrated, flicking back and forth between fin and foot.

She tried to mimic him. Her adorable features screwed up in concentration. “Do it slower.”

Slower made the movement more difficult. Like focusing on breathing could cause choking in the lungs.

“You can’t blame me for choking like that,” she said, responding to a thought he hadn’t meant to transmit to her. “It was my first time! Normally breathing underwater is death, if not from actually drowning, then from the bacterial infection and pneumonia you get afterward. Oh!”

She flexed her foot in the right way. Her two smallest toes flattened and the foot half expanded. She kicked, wheeling in a lopsided circle. “This is awesome!”

Her light shone so brightly it made his heart ache.

But she couldn’t get her second foot to relax into the correct shape, and her first one flexed back to a human foot when she wasn’t paying attention. After working herself into sweaty frustration, he put his hands on hers to stop her from being too violent with herself.

“It just won’t go,” she cried.

“You have mastered breathing and communicating underwater,” he told her. “Forgive yourself if you must practice longer to achieve flight.”

She blew a stream of water out of her mouth. Her bangs danced. “I’ll get it.”

“You will.”

She brightened. His faith in her made hers stronger.

Again, his chest ached.

This precious woman captured him. The ache was the feeling of his heart stretching to hold their love. No other would ever take its place. He would protect her with his life.

He drew her arms around his neck. “Hold onto me. This first flight will be mine.”

She nestled against his chest. “Don’t drop me.”

“Never.”

He kicked powerfully. They rocketed from the cave, shooting past the occupied cave guardian, and wove through the atoll formations to open sea.

“Whoohoo!” she cried, clinging tight.

He held her safe, suctioning her softness to his body.

This was how all mates were meant to travel. Once she grew her fins properly and adjusted to the permanent change, they would forever travel the seas together in their mated pair.

Such a wonderful future dazzled him.

“Hey, I meant to ask. What’s that strange noise?” she asked. “It’s behind us now. It’s like singing, only really off-key.”

“Probably Mr. Huggles,” Torun said, adopting her name for the cave guardian. She would name many more things in their ocean, and he wanted her to feel proud of doing so. “Their songs are loud and terrible, especially after they have collected a new object.”

“She did steal my grease pencil.”

“It is now her new favorite possession, and she is announcing it to every other guardian also.”

She swallowed. “I’m kind of touched.”

He squeezed her. Her empathy, like her kindness, resonated in her soul.

“I’m also sorry I made her sound worse.”

“Do not be. Their awful song gives warning for miles. You can navigate half the ocean by taking cave guardians as markers. It is as reliable as your GPS.”

“Do we sound as awful to them?”

Did they? All living creatures sang. Even inanimate rocks possessed a song under the water. The mer must also have a soul sound.

“Don’t assume it’s beautiful,” she said. “Or, at least, not to everybody. What if we sound like sandpaper or a diesel engine backfiring? Or squealing brakes, or nails on a chalkboard.”

“We sound like no such thing,” he said. “We sound like solemn tones.”

“Perhaps we toot.”

She made him laugh. The absurdity of it all. Human women would turn mer warriors into philosophers.

“Or scientists,” she said. “If we can measure animal and rock sounds, we can measure our own.”

Again, she had picked up thoughts he was certain he had not projected into words. No, words had not vibrated in his chest. How odd.

“It’s so bright,” she said, changing topics and staring out across the wide undersea sky of the ocean. “I can see so far.”

“More than before?”

“So much. I can see tiny plankton on the surface miles away. I can see Mr. Huggles hanging out behind us in her cave. Ocean currents move like clouds. It even feels like I can see through rocks to the other side.”

Not only her eyes informed her new vistas. Her senses changed to become sensitive to sound, taste, and the deeper waves of life energy.

All objects and creatures gave off a resonance. Some part of the resonance Lucy now experienced as their song. Other parts of the resonance she experienced as light. Some as taste.

He had struggled, at first, to handle the opposite problem on land. He could only see so far, and he experienced air as a cold, empty, silent vacuum.

“Are you ready to go faster?” he asked.

“Faster? But we’re already out-pacing schools of fish.”

“We are approaching a finger of the super-accelerated Sol Sud current. We have a long way to reach our city.”

Her eyes opened wide. “Yes!”

“Hold tight.” He arced into the current and flew.

She laughed with joy.

Torun flew fast within the current at first to show off; then, he flew for the joy of doing so. How long since he pushed himself to achieve his peak efforts? Chasing mini-accelerated currents within the main one, he flew ever onward, ever down.

When he had been a young fry, his wise elders took him to safe fields near the city to learn his abilities and to fly. When he had grown older, he tested himself against dangerous creatures, pitting his life against his speed to overcome certain death and survive.

Now he flew in his mating dance, pushing himself to ever greater bursts, astonishing and delighting his bride. Joy suffused her, and she opened her eyes to gaze all around.

Soon they would reach his village and he would enjoy her in the privacy of his castle. Thick walls would keep out danger and muffle their passion. He kicked harder.

They traveled far. When exhaustion finally took him, he drifted in the current, resting while she also dozed. He did this several times until reaching the place to exit the current. He swam through slower, overland currents to his city.

Lucy asked a number of questions, which he answered as best he could.

Yes, the mer were good at avoiding detection. No, he did not know if the mer were descended from humans or sharks or whether they were extraterrestrial aliens.

Once they had moved easily between earth and ocean. After the war, about a thousand years ago, the mer had withdrawn from the air. Only brides of the sacred islands honored the ancient covenant to provide young fry.

“And now, you,” he said.

“Now, me.” She stroked the back of his neck. “God, I hope so.”

He squeezed her.

They approached the border of Sireno’s land. Coral spires rose from the ocean floor, marking the beginning of the towering outer reefs. In the distance, glowing bulbs formed the floating city. The Sireno cave guardian warbled from his cave to the east.

“You really can hear those cave guardians,” she said with a laugh. “This one sounds like a cat being strangled by a frog.”

“Yes, he is a lonely male.”

Torun slowed. Passing between the spires placed them in dangerous territory. They could be heard by warriors lying silent.

Lucy ignored this danger. “If he’s lonely, why doesn’t he go to meet a female? Mr. Huggles had no guy.”

“Mating is dangerous for cave guardians. Sometimes one is not in the mood, and the other may get eaten.”

She stilled. “That’s not what happens when we mate, right?”

“No.” He lowered his vibration. “We are not cannibals. Shh.”

“Good,” she whispered, “because I don’t want to turn into some red-eyed zombie vampire squid.”

“Yes, that would be quite unsettling. We are normal. It is fine.”

Hmm. The guard towers above the spires were empty. No evidence of recent patrols marked the reef.

He approached the echo point, an intersection of currents where he could hear all around them. All around could also hear them. The water was clear and still. The tinkling chimes of the distant Life Tree, the peculiar song of Sireno the city, amplified.

Something wasn’t right….

She shifted, clearly still anxious about his last revelation. “By n—”

“Shh!”

Their voices projected outward.

But still, the city was silent. Emptied, as though not even a single guard had been left home.

How very, very odd. The only time that could happen was during the death of the Life Tree.

Or an attack.