Episode 4

 (Korean: 도미노, lit. "Domino")aired on June 22, 2019.

Synopsis
Oh Won-sik makes a move that jeopardizes Tae-jun's standing with Song Hui-seop. Seon-yeong gets a surprise visit. Do-gyeong learns about Hye-won's past.

Cast

 * Lee Jung-jae as Jang Tae-joon
 * Shin Min Ah as Kang Seon-yeong