Lee Yool falls off a cliff and nearly dies in an attempted assassination. He loses his memory, and wanders for 100 days under a new name and personality. During this period, he meets Hong Sim, head of the first detective agency in Joseon.

Cast: Doh Kyung-soo, Nam Ji-hyun, Cho Seong-ha, Cho Han-chul, Oh Yeon-ah, Ji Min-hyuk