Umut and Sarp’s father, Metin, works as an assassin for one of the most powerful mafia leaders in Istanbul, Celal Duman (Çetin Tekindor). When Metin is arrested and imprisoned, Celal kidnaps three-year-old Umut in order to make sure that Metin will not betray him. Sarp and his mother Füsun (Nihal Koldaş) never learn the truth about Umut’s disappearance, as Metin dies in prison without revealing anything. They both think Umut is dead after the police bring them his blood-stained T-shirt, and Sarp grows up blaming himself for what happened to his brother and being constantly haunted by his loss.
Years later, Sarp is expelled from the police academy a week before graduation by his commander, Yusuf Kaya (Mustafa Uğurlu). At the graduation ceremony, he attacks Yusuf and is sent to prison for a year. It is subsequently revealed that Sarp and Yusuf planned everything in order for Sarp to infiltrate Celal’s group as an undercover officer and help to arrest him. Sarp is even more determined to take down Celal after finding out that he was responsible for Umut’s disappearance. Things take an unexpected turn when Sarp finds himself falling in love with Melek Yıldız (Bensu Soral), Celal’s protégé and lawyer, who, unbeknown to him, is very close friends with his own brother.
Umut, renamed Mert Karadağ, doesn’t remember anything about his family and is loyal to Celal, believing that he saved him and Melek from the abuse they had to endure on the streets. He becomes a police officer and is subsequently accepted into Yusuf’s team, where he acts as a spy for Celal. After he falls in love with Eylem Aydın (Damla Colbay), Sarp’s childhood friend, his loyalty for Celal is repeatedly tested to the point that he is starting to have doubts about his actions. Mert develops a close relationship with his own mother, Füsun, and a fierce rivalry with Sarp, completely unaware that they are his true family.