Myeong-jun and Ro-hee find themselves in Choi Jin-tae's villa. Myeong-jun learns of "The Genius Child Project," a brain experiment Ro-hee was a subject in. Dr. Mo attempts to separate Ro-hee and Myeong-jun. Meanwhile, Sang-yun digs into a case from 30 years ago to catch the culprit of the hospital director and his wife's murder case and hears an unexpected name from a witness of a past case.