Kali Wallace studied geology and earned a PhD in geophysics before she realized she enjoyed inventing imaginary worlds more than she liked researching the real one. She is the author of science fiction, fantasy, and horror novels for children, teens, and adults. Her most recent novel is the science fiction thriller Salvation Day. Her short fiction has appeared in Clarkesworld, F&SF, Asimov’s, on Tor.com, and other speculative fiction magazines. After spending most of her life in Colorado, she now lives in southern California.