Brothers Ugur and Lokman Bulut are locked in a bitter inheritance battle and need a sample of their mother's DNA to contest her Will. But when her body is exhumed, her corpse is found to be missing and a fresh body, with its heart removed, has been put in her grave. Assigned to the case, Inspector Mehmet Suleyman quickly realises that the heart has been illegally harvested, and his team has a murder inquiry on its hands.

Meanwhile, retired inspector Cetin Ikmen is tracking down a missing person: Sevval Kalkan, a once-famous actress, who has joined an underground movement called the Moral Maze, whose mission is to help the destitute living on Istanbul's streets. The unidentified body in the grave cannot be Sevval's, but her shocking reappearance leads Ikmen to fear that she, too, is a victim of organ harvesting...

Joining forces, Suleyman and Ikmen confront Istanbul's darkest underbelly to expose the horrifying truth of a city in crisis.