Fenlee's opal necklace had always radiated a certain warmth since her mother's death. But now, at sixteen, her world begins to unravel as the stone sparks to life, revealing itself to be an otherworldly artifact of untold power.

Between her mechatronics studies at the academy and scavenging expeditions beneath the sprawling city of New Cascadia, Fenlee and her adopted brother, Elliot, try to decipher the mysteries of her necklace and its link to events in Fenlee's past.

But they're not alone in their search.

Strange undercity dwellers offer cryptic warnings, drones track their movements, and deadly corporate agents lurk in the shadows. When tragedy rips Fenlee's family apart, she must learn to use the artifact's power to save those who are deeply precious to her. But nothing can prepare her for the dark truths that she will uncover on that journey...