Hyper Knife

Once a brilliant neurosurgeon but now a pharmacist in a rural town, Se-ok still performs brain surgeries at night. Se-ok is confronted by Deok-hee, the mentor who had a hand in stripping her of her medical license and ruining her life.

Deok-hee wants Se-ok to operate on him for a tumour in his head, but Se-ok does not want to comply with her mentor's request. Frustrated by his former pupil's reluctance, Deok-hee puts pressure on Se-ok.

Se-ok wants revenge for what Deok-hee did to her and meets Na-nae in the hope of stopping Deok-hee from winning the Ichida trophy, an award he is poised to win for the tenth consecutive year.

Se-ok is in search of Deok-hee's weaknesses. She visits a former patient, Kim Myeong-jin, who is the main reason for Deok-hee's betrayal, and asks him why he wanted to erase her from his life.

Se-ok's past comes back to haunt her when Doo-bong, a former patient, calls and warns her of a threat coming her way. To make matters worse, a sudden house fire pushes Se-ok to the edge.

A rich patient requires a highly complex surgery that needs two skilled neurosurgeons. Deok-hee comes on board, taunting Se-ok and telling her he wants to see what her world is like. Stuck with no other choice, the two reunite at the operating table.

Se-ok assumes that Deok-hee's ailment only requires surgery, but learns from U-yeong that his condition is terminal; she prepares for the surgery and calls Deok-hee, telling him to come right away so she can operate on him.

Se-ok's past begins to resurface as she tries to blackmail Deok-hee into being treated; after causing confusion as a medical consultant in an investigation, Deok-hee makes a deal with Inspector Yang.