Follows three young operatives of a Psychic Detection Agency as they battle an epidemic of ghosts in London.

"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 he 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...

Twelve-year-old Sophie discovers the abilities that have always caused her to stand out are because she is actually an elf and, after she is brought to Eternalia where she can hone her skills, Sophie learns she harbors certain secrets that others would kill to learn.