Dr. Jin-Hyuk (Song Seung-Heon) is a gifted doctor who was born in a family of doctors. Jin-Hyuk is confident and fully aware that he is the best neurosurgeon. His success rate hovers at 100%. Due to his talents and success, Jin-Hyuk is unable to understand how others fail. His girlfriend is Yoo Mi-Na (Park Min-Young). Unlike Jin-Hyuk, she is bright and unable to ignore those in need.
Jin-Hyuk awakes in the forest at night. He sees a group of people wearing traditional clothing and fighting each other with swords. At first, Jin-Hyuk thinks he is on a filming set, but soon finds himself surrounded by the men and realizes it is real. Military officer Kim Kyung-Tak (Kim Jae-Joong) gives an order to catch Jin-Hyuk. Jin-Hyuk runs from the men and is saved by Lee Ha-Weung (Lee Beom-Soo). Jin-Hyuk tells himself 'I have to go back'.
The next moment, Jin-Hyuk is back in the hospital and receives a phone call that he has to perform surgery. During the operation, Jin-Hyuk hears the words 'I have to go back' and his head begins to hurt, but he ignores the pain. He soon discovers a fetus inside the man's brain. Due to the rarity of the situation, Jin-Hyuk keeps the fetus for later examination.
Jin-Hyuk plans to propose to his girlfriend Yoo Mi-Na. While Yoo Mi-Na is doing volunteer work to provide medical care for the poor she sees a man that collapses. Yoo-Na takes the man to the emergency room and contacts Jin-Hyuk. D. Jin-Hyuk tells Yoo-Na that the man won't survive. Yoo-Na becomes upset and drives off. While still in view of Dr. Jin-Hyuk, Yoo-Na gets into a car accident. Jin-Hyuk performs surgery on Yoo-Na. During the operation he again hears the words "I have to go back."
Later, Jin-Hyuk is in anguish and stands on the rooftop of the hospital. A man walks onto the rooftop. He's the patient that Dr. Jin-Hyuk performed surgery on and had the fetus in his brain. The man is now carrying medical tools and the fetus. A struggle ensues between Jin-Hyuk and the man. Jin-Hyuk falls off the building with the medical tools. The next moment, Dr. Jin-Hyuk finds himself in the Joseon Period once again.
Jin-Hyuk is soon chased by the police in the Joseon Period and, while being chased, he sees a woman who looks exactly like Yoo Mi-Na.
