Katerina Lebel is the sole surviving heir of her father's Cobalt and iron mining businesses, until her overbearing aunt moves in. Kate has a unique quirk that sets her apart from others, who consider her cursed--ever since a childhood accident involving the mysterious and deadly substance Cobalt, she has woken up each morning with a new face. Now almost fourteen and fed up with her aunt's abuse, Kate sneaks onto an airship bound for the distant seaport. Anthia, a hardened and boyish teenage guard, discovers Kate and takes pity on the young stowaway. Disaster soon strikes, and the girls must fight for their lives in a forest teeming with giant, mutated wildlife and murderous trees hungry for human prey. On their journey, they join with some unlikely companions to discover Cobalt's effects on whatever it doesn't kill. And Kate finds secrets deep within the trees that may shape her destiny--if she can make it out of the forest alive.