When a dead historian is discovered in a sealed, unmapped Alcatraz ward with seawater staining her hands and five chilling words scrawled in the dark. He was never discharged. FBI Special Agent Adrianne Weiss expects a standard murder case. Instead, the infamous prison begins answering her by name as cameras slip through time, unpowered radios broadcast voices, and a 1942 forbidden experiment points directly toward the dark history of the Weiss family.
As a fierce storm locks the island down, Adrianne and her partner, Celia Moreno, unearth vanished prisoners, ominous patient numbers, and an ancient presence trapped beneath the ward. To solve Dr. Isolde Renard’s murder, Adrianne must confront the buried secrets of her father, a forgotten child, and the entity still pounding from the abyss.