Episode 1

S1 E1: After her divorce from her rich husband, Joong Eun makes a living by working at factories late at night and concealing industrial accidents. Joong Eun\u2019s previous co-worker, Il Sun, runs into Joong Eun at Sungrak Industry while investigating the scene and asks her to join UDC, Undiagnosed Disease Center. Meanwhile, Joong Eun rejects Il Sun\u2019s offer.