Major Kemal joins the imperial forces, presenting himself as a supporter of Çerkez Ethem and the sultan. His goal is to discover the identity of the agent who has infiltrated the National Struggle. Kemal rises to the rank of major thanks to his military successes during his time as a spy. However, his brothers, Captain Nazmi and Lieutenant Mustafa, who are unaware of this situation, become hostile towards him. Meanwhile, İsmail Hakkı Bey, Kemal's only source of contact, is killed. Kemal continues his communication through his daughter Perihan. On the other hand, he falls in love with Nilüfer, his brother Nazmi's girlfriend. The love between the two becomes complicated when it merges with their espionage relationship.