At age twelve, Sophie learns that the remarkable abilities that have always caused her to stand out identify her as an elf, and after being brought to Eternalia to hone her skills, discovers that she has secrets buried in her memory for which some would kill.

Sophie Foster is on the run - but at least she's not alone. Her closest friends from the Lost Cities have gone with her to join the Black Swan. They still have doubts about the shadowy organization, but the only way to find answers is to start working with them. As they settle into their new lives, they uncover secrets far bigger than anything they'd imagined. But their enemies are far from done, unleashing a terrifying plague that threatens the safety...