This story was inspired by an episode in the ancient Irish legends of Finn mac Cumhail, famous leader of the Fianna. The original story, or one version of it, goes like this:
Finn was hunting one day, and he and his men were chasing a strange white fawn. The fawn was surprisingly fast, and gradually the men and dogs began falling back, until only Finn and his two wolfhounds, Bran and Sceolan, remained. The dogs finally overran the deer, but to Finn’s surprise, when he caught up he found the white fawn resting on the grass, with the dogs gamboling and playing joyfully about her. Finn realized this was no ordinary deer and spoke gently to her. The fawn followed him home, and he commanded she was not to be harmed.
That night a beautiful woman appeared before him. “I am Sive,” she said. “I am the deer you spared on the hunt.” She was a woman of the Sidhe, and she explained that a dark druid, Far Doirche, had pursued her. He grew angry when she rejected him, and in punishment had laid an enchantment on her and turned her into a deer. (In other versions, as in my story, Sive turns herself into a deer to escape him.) Sive told Finn she had wandered Ireland for three years as a wild deer, until the dark druid’s servant took pity on her and told her that she would be safe within the walls of Finn mac Cumhail’s dun.
Finn fell instantly in love with Sive, and not only offered her shelter but married her. They were very happy together, but one day the Fianna were called upon to protect Ireland against an invasion, and Finn had to leave Sive behind.
Sive waited anxiously for his return. One day, she saw Finn climbing up the road to Almhuin with his two dogs. Too excited to wait for him, she ran down the road to meet him. Too late she realized it was not Finn coming toward her but the Dark Druid himself, wearing an enchanted disguise. He raised his hazel wand, and the last the servants saw of her, she had been turned into a deer and was being dragged by the neck into the forest. They tried to follow, but Far Doirche’s enchantments confused and tricked them, and they stumbled around in the fog after false voices without ever finding their quarry.
Finn was heartbroken on his return and searched everywhere for Sive, but he never saw her again.
However, six years later he and his men were hunting boar on Ben Bulben, when the dogs set up a great hue and cry. The men rushed after them, and Finn was astonished to find Bran and Sceolan set against the other dogs, keeping them away. Behind them sat a little, long-haired, naked boy. And Finn thought there was a look of Sive about his face, and that he might be her son. He took him home and named him Oisin—little deer—and when the boy was less frightened and found his voice, he told them that he had indeed been raised by a deer. They lived in a cave and had everything they needed there. But from time to time, he said, a Dark Man would come. He would speak nicely at first, but Oisin’s mother would huddle away in fear, and then the Dark Man would become angry. The last time he came, he drew out his druid rod and struck the deer, and then he led her away. And though she cried pitifully and tried to go back to her son, she was not able but was compelled to follow the man. And though Oisin tried to follow, an invisible barrier held him back. He fell insensible, and when he awoke, he was on the mountain all alone.
That’s the last we hear of Sive in the legend. But Oisin’s story continues. Years later, when he is a great champion of the Fianna, Niamh does appear to him, profess her love, and take him away to live with her in Tir na nOg. He stays with her for three years and then wishes to return to visit his father and friends. He travels back on Niamh’s white horse, only to find that in Ireland three hundred years have passed, and everything has changed. But that’s another story!