When mathematical genius CEO Noh Go-Jin begins to receive death threats from an unknown person, he hatches an elaborate plan to track them down. Shortly after the start of his plan, Lee Shin-ah, an introverted hard-working secretary who has recently been diagnosed with a life threatening disease and plans to take her revenge for her poor treatment at his company, discovers Go-Jin in an unusual situation. What ensues is a sweet and, at times, grisly romance between the pair that will have viewers reeling as they swerve from twist to twist.
