"Gu Family Book" Lee Sung Jae discovers who Lee Seung Gi's parents are.

May 14, the 12th episode of the MBC drama "Gu Family Book" featured Jo Kwan Woong (Lee Sung Jae) learning about the secret about Choi Kang Chi's (Lee Seung Gi) birth.

Park Chung Jo (Lee Yoo Bi) becomes shocked after seeing Choi Kang Chi turning into a beast to attack her older brother Park Tae Seo (Yoo Yeon Suk). Choi Kang Chi takes Park Chung Jo to the secret place in the mountains but she tells him, "There is no way you are Kang Chi. You are not Kang Chi. There is no way Kang Chi would try to harm my brother" and runs away.

Park Chung Jo gets caught by Jo Kwan Woong's men in the mountains. Ma Bong Chool (Jo Jae Yoon) tells Jo Kwan Woong, "When he took off his bracelet, he turned into a beast. He was so strong that he stood unaffected even when we all attacked him together."

Jo Kwan Woong remembers Goo Wol Ryung (Choi Jin Hyuk) and Yoon Seo Hwa (Lee Yeon Hee) from the past. Jo Kwan Woong realizes that Choi Kang Chi must be their son and mutters to himself, "There is no way..."