It's been seventeen years since the internet crashed and left the world broken.
Auli lives on the Bellwether, a floating college safe from the conflict of the mainland, where she studies the Oracle - an uncanny girl who channels dangerous ghosts and provides lost information about the world's seas.
Her peaceful world is shattered when her beloved mentor, Boudain, is found dead. While most aboard believe it was due to natural causes, Auli discovers hints that suggest he was not the benign leader he seemed - and that his death might be deliberate.
Surrounded by people with their own motives and secrets, Auli doesn't know who to trust. Worse, the Oracle is attracting dangerous, mutating ghosts that threaten everyone aboard. With the Bellwether fracturing from internal and external pressures, she is forced to wrestle with a life-changing decision: save the Oracle or save the Bellwether - and all the lives that depend on it.