King Sukjong Meets His Son - S1.E45

Dong Yi and Geum live outside of the palace with the commoners but Geum is desperate to find out who his father is. So, he sneaks into the palace but bumps into Jang Ok Jeong's son, the Crown Prince. Then, Jang Ok Jeong turns up and wants Geum to be beaten because he dares to come near the Crown Prince. But the Crown Prince saves him and he is allowed to leave unharmed. Geum then meets a nobleman and talks to him without realising that the nobleman is his father, the King.