L.U.C.A.: The Beginning Season 1 Episode 4

Ji O remembers that he burned down the orphanage as a child and is in a state of shock. Gu Reum takes him to Jong Hwan at the NFS where he undergoes a number of tests to find out about himself. However, Ji O recalls more horrific memories while being poked and prodded. He runs away and ends up going to see an old friend.