“They’re quite frisky,” Liz said handing me a bandana to wipe my face.

“They’re ready to migrate,” Soheila said, pointing to the far side of the pool. At first all I could see were rapids spilling into a fast flowing stream, the clear water twisted into skeins of transparent silk where it braided over the rocks, but as we moved closer I saw that those transparent skeins were actually long thin bodies, slender as eels, slipping over the rim of the pool and into the stream.

“Those are undines?” I asked, recalling the illustrations of the winsome maiden Arthur Rackham did for the German fairy tale. She had looked far different from these eel-like creatures.

“Immature undines,” Soheila replied slipping her fingers in the water and tickling the underbelly of one of the undines. It flipped over and stared at us with its large mossy eyes. Up close I saw that it did have arms, but they were loosely clamped to its sides by sheer, web-like netting. On some undines the netting had frayed to long streamers, freeing their arms. “Their arms start to separate from their bodies to help with their passage, but their legs won’t form until they get to Faerie. That’s why it’s so important that they get to Faerie. If they’re stranded here …” Soheila shook her head sadly. “They can’t survive past the summer here in this form. Poor things. During the last migration we found several dead ones stranded in the woods.”

While I knew Soheila was ancient, it still unnerved me when she spoke about events that had taken place a hundred years ago as though they had just happened yesterday.

“Let’s hurry,” Liz said, striking out down the narrow path beside the stream. “The first wave will be reaching the junction pool by now.”

I followed the women who now walked single file – Liz in the lead, followed by Diana, then Soheila – trying to keep up with their accelerated pace, but I found myself distracted by the activity in the stream. If I hadn’t known about the undines I might have thought the water was just running fast – as these mountain streams ran during the spring thaw or after a heavy rain. But it was the end of June and it hadn’t rained in a week. Nor could the water pressure explain the way the stream leapt over its banks, spraying bright arcs into the air, or the way the stream sounded. Beneath the rushing water was the sound of laughter – the raucous, wild twitter and screech of excited teenaged girls.

“Are all the undines female?” I asked, watching a slender shape break from a wave and pirouette in the air before gracefully diving back into the stream.

Soheila paused and looked back at me. She seemed unsure if she should answer, glancing nervously ahead on the path toward Diana, but then she answered in a low voice. “There used to be male undines, but during the last spawning there were only a few. We fear there might not be any this season. We’ve noticed that many of the indigenous species of Faerie seem to only produce female offspring – and a few only produce males and others simply can’t reproduce anymore. It’s a source of great concern in the fey community because it means, of course, that many species will die out unless …”