Zeynep and Hakan race against time to find Nisan, a chemist who's their only hope for a cure. A shadow from the past returns.

Vizier, the mysterious leader of the Immortals, curbs Rüya's ambitions and lures Hakan into a trap using Levent. Faysal makes a vindictive decision.

Hakan and the Loyal Ones hatch a scheme to gain Rüya's allegiance. Vizier demands Faysal's help in retrieving the last piece of the key.

The Oracle shares an ominous vision, Hakan visits the past, and Zeynep overhears Vizier confronting Rüya about the key.

A mysterious symbol offers Hakan a clue as he scrambles to uncover Vizier's identity, but his omnipresent foe stays a step ahead.

Nisan accompanies Hakan in his search for the key's missing piece. Vizier threatens to drive Hakan to the edge as a shocking truth comes to light.

Galvanized by a centuries-old betrayal, Vizier turns all of Istanbul against Hakan in a fateful coup de main.