When Lee Se-Won (Lee Sun-Kyun) was a child, his mother died in a hit and run accident. He decided afterwards to become a brain scientist. He is a genius and he remembers everything he sees. 20 years after his mother’s death, Lee Se-Won has become a famous Ph.D scientist in the brain science field. One day, a mysterious person contacts him and asks him to extract information from the brain of a man who committed suicide. Lee Se-Won is interested and accepts the proposal. He attempts to extract information from the dead man’s brain, but fails. A couple of days later, he finds himself behaving differently and seeing things differently. Lee Se-Won looks into the dead man’s case. Dr Brain