It's the summer holidays, and Eddie finds himself strangely drawn to the famous caves at Wookey Hole. He makes friends with the ticket seller there, and before long is allowed to roam wherever he wants. He loves it . . . until the day he gets lost. Just as panic sets in, his hand is taken by a strange girl, about his own age, who guides him to the surface. Gwerren is weird. She's extraordinarily pale with huge violet eyes and white hair - what's more, she won't come out of the caves. As she and Eddie become friends he starts to wonder if she's a ghost. Then Eddie nearly dies in a pothole - and discovers not only the truth, but life where nobody thought it could be.
