Brief explanation: I've written a rather lot of merperson mythology. The solstice child is believed by the aqueans (merpeople) to be the one who will end their world. So what, logically, should his mother do when he's born?
She could no longer ignore the signs.
A golden child, he was. That she couldn't deny, even if she wanted to—his eyes and scales were amber and sunsets. But so had her grandfather been, and he hadn't been the solstice child, now had he?
But her grandfather hadn't been born in the darkest hour of the summer solstice, thanks to his parent's foolishness in conceiving him at the right time of year, thanks to his mothers foolishness in traveling despite being heavily pregnant, thanks to the warm summer night that hadn't killed him instantly with the shock of cold like most babies. That she could ignore, or deny, or tell others differently—for all anyone but she and his father knew, he had been born two days after the solstice. Still close, but clearly not the prophesied child, just enough to save him from suspicion and ire.
But she knew differently, and her own suspicion was one she could not save him from.
Born on the summer solstice solstice, when seven (and she'd counted, and his father had counted, and both shook their heads and desperately, desperately hoped they had counted wrong) stars had fallen across the night sky, a golden child. They whispered quietly to each other—should they let him live? If he was the child of prophecy, then to save their world—to save themselves, their family—he had to die. Was it not better to kill him before he had the chance to know his fate?
But no. No. They could never—would never. The golden child had lived, in the hopes that he was not the child they thought he was, that he would grow to be insignificant and normal, and live a happy life regardless of the foolishness that gave it to him.
But they knew, from the time he was old enough to swim away, that this was a false hope.
The dolphins loved him. His father had started to think he would go insane if he had to listen to their chatter for one moment longer—but the child laughed as the friendly bunch poked their noses into his soft belly. When he began to swim, they swam with him, chattering so fast that not even the elder of the pod could understand their language. He learned to hunt among the dolphins before he learned among his pod, and chattered with them in the bright squeaks and whistles. His mother almost smiled.
And the dolphins shall know him, as they know my child Feldspar, and they shall teach him...
Almost as soon as he'd learned to speak, he'd learned to sing. He started off simply—a single toned voice much like any other child, singing back the songs she'd sung to him as a baby. But there were other melodies, that emerged not long after, blending into two vocal tones, then three, then four—an impressive voice, even for an adult, and especially impressive for a child. But the songs were different, with words and phrases he'd never heard, then ones his parents had never heard. She didn't want to ask.
Illa shall sing with him, and teach him all her songs...
On occasion, they would visit the shore, and lie on their backs on the smooth rocks at low tide. He would lie next to her, nesting between her arm and the bend of her hip, staring upwards in wonder at the stars. She asked him what he saw, and tried very hard not to cry as he identified the constellations, one by one, without ever being told.
She didn't want to believe it.
The stars will be as simple as the water, as Somin tells all he knows.
He loved to play, with the dolphins or anyone who was willing. The dolphins didn't play with him as much when their pod joined to a larger one, but there was still always a few tagging along behind. The other children—who were always bigger or smaller than him by half a year—taught him a few games. The dolphins foiled his every attempt at hide and seek. He was a fair shot at tag. He lagged a bit at catch-the-otter, but that was alright. But he came up with new games, other games, and soon the adults began to ask their children where these strange games had come from. They told, and he was asked.
“There's someone in a dream who tells me about them,” he said. “Just like the one who told me about the stars.”
And Hollin shall teach him games, as he has always taught my children, and he shall play...
It was possible, at this point, for her to still imagine he was not the solstice child. The six children of legend had been known to visit some in dreams and teach them great things, and though it might have been a stretch of the imagination to believe that four of them would bless her child, it was not impossible. And even a desperate hope is better than none.
But she still knew, in her heart, that he was.
They left the new pod not long after that.
They found ruins, from before Alanti, and stayed there for a few days. The buildings were alien to all of them, the carvings barely perceptible, and the runes meaningless—but he understood them. She found him explaining to one of the younger children what the carvings meant, what the runes meant, the stories they told, as clearly and as plainly as if it were as simple as what fish you would eat and what would eat you. She could not turn away, as if in horror.
Karo shall teach him words, letters, all that shall be lost to you...
It was in his twelfth year, at the solstice festival, that she finally, finally, could not deny it any longer. The elder was telling a story, that he had never heard—she knew he had never heard, for it was one she hadn't heard since she was a child, one of those stories that by tradition was only told every fourteen years, to mark the fourteen the solstice child would one day (not yet, she hoped) be among them. He nudged her again, and again, until she finally whispered, “What?”
“Mama, he's got the story wrong!”
She asked him how. He told her the way the story was supposed to be—the way she's heard it as a child. When he finished, she realized the whole gathering was watching him, listening in rapt attention to the true and real story. The elder had fallen silent.
So she asked him, late that night when none were listening, where he had heard the story, and why he knew it so well.
“She tells me—a girl a lot older than me, but not a grownup. She's purple.”
“Is she like the one who told you about the stars?”
“And the songs, and the runes, and the games, and the dolphins, Mama!” He nodded. “They talk to me when I'm sleeping.”
And Urma shall tell him her stories, though they may pass away in time, he shall know them...
“How many of them,” she'd asked carefully, “do you see?”
“You mean six,” she corrected quickly, hoping so desperately he was wrong.
“No, Mama. There are seven.”
Though all may see these six in dreams, to hear the stories or learn the stars, only the Child shall see the seventh.
And Antioch shall guide him.
She could not deny the signs any longer.
They had to kill him.
She didn't want to. What mother would, what father would? They loved him, even if he was the solstice child, even if the world would end, he was still their child, their only child. They made a knife from obsidian shards, and tucked it away with a quiet promise to each other that tomorrow, tomorrow, the deed would be done.
Tomorrow came and went, again and again. The deed was not done, never done, not for another year. He was only twelve, they still had time—another day would not destroy the world. His father gave him the knife as a present two days after his thirteenth birthday, on the day he thought he had been born.
He was old enough to hunt on his own, among the dolphins that still followed him. He was old enough to wind shells and coins and tattered rope into a bracelet for his mother, and another for himself. He was old enough to understand and fear the coming of the solstice child.
He was not old enough to understand that he was the solstice child.
The days flickered past. She knew they had to kill him soon, before the fourteenth year, before he was taken from them and all hope was lost. His father became a little more resolute on the matter, steeling his nerves, determined not to force his wife to do it. They made another knife, larger, more deadly—the first one had gotten a little chipped in the hands of their son.
They would explain it to him. It wasn't fair any other way—his mother wished more than anything that they had killed him before he was old enough to love them. He had to understand what he was, what he was destined to do. How that destiny had to be fought. Why. The death would be swift. She knew it would still be hard, still be painful. But he would at least know, and his spirit would be free to wander.
But the days still washed by them like waves, and time was running short.
They fixed a date. The day they were intended to leave for the solstice festival. He would be sent out to hunt, so they would be late. The others would leave them behind, and they would be free to do the deed alone. He would return, ask where the others had gone, and it would be explained. The deed would be done. The world would be saved.
He was sent off to hunt.
The others left.
And they waited.
And he never returned.
She did not know if Antioch had guided him away from them, or if he had understood more than they knew. Perhaps some chance circumstance had done the deed for them, a shark, an orca, a fisherman's net. She grieved for him if he was dead.
She grieved for the world if he were alive.