David's life was pretty normal. School. Friends. Girlfriend. Actually, Senna was probably the oddest aspect of his life. She was beautiful. Smart. But there was something very different about her. Something strange.And on the day it began, everything happened so quickly. One moment, Senna was with him. The next, she was swallowed up by the earth. Her screams echoing from far, far away. David couldn't just let her go. Neither could the others. His friends -- and hers. So, they followed. And found themselves in a world they never could have imagined.Now they have to find Senna and get home without losing their lives. Or their minds. Or both....