The full power of the freezing water crashed into them, knocking them off their feet, snatching Tara's breath away. She managed to hook one arm around the handrail, trying her best to hold onto Lucy with the other. As one side of the bridge collapsed, Lucy's feet scrabbled to keep a footing, but she slipped down the wooden planks. Tara lost her grip, but managed to grab Lucy's hand as she held it out. She was left dangling over the water.';I can't hold on, Tara. Don't let me fall! Please don't let go!' Lucy begged, her hand beginning to slip from Tara's. There was no time to think. ';No, I won't let you go, Lucy.' With that, Tara let go of the handrail and they plunged together into the raging torrent. Tara realises there is something strange about herself when every time she goes into water her fingers begin to web and legs feel funny. But then her sister Niamh is a changeling, a fairy child exchanged for a human child ten years before. Now it's time for Niamh to return to her own world, and Tara and friends, Lucy and Jared, intend to go with her.