Eylul the stubborn, school girl turns up to be a strong professional doctor by the help of her teacher Ali Asaf. After years of separation they meet up again but not as a teacher and student, instead as surgeons working side by side. Their love is met by many challenges and the inner conflict of the stubborn women who refuse to yield easily to her heart, refusing to repeat the miserable story of her dead mother.
When two businessmen kill off the third partner in their company there is one crucial witness to the murder - the victim's young son. The killers arrange for the little boy to meet the same fate as his father, but the hired assassin can't go through with it and sends the child away. After years of separation remembering nothing of his origins, the boy Efe returns as an adult to discover he has a twin brother. His brother has taken a job at their father's old company - and married Efe's childhood sweetheart. When their witness returns, the original murderers set about taking care of him once and for all. But when they get the wrong twin, Efe who has been brought up as a humble fisherman, has no option but to adopt his brother's high-flying identity and lifestyle to infiltrate the inner circle that has destroyed his once powerful family. Winter Sun follows Efe's quest for revenge and redemption, as well as a love denied him since childhood.