Mystery 1973 which episode is Dr. Cao in Chichiwa?

Mystery 1973 and Dr. Cao are the 20th episode.

Episode 20 Summary:

According to the current situation, Rosantian was divided into two factions. One group continued to search for Li's body, focusing on Jiren Hospital, because Li's body had once appeared in Jiren Hospital.

The other group went to find the woman who took the watch. Luo Sangtian went to Ren Ren Hospital alone, and unexpectedly found that nurse Wang Qianqian was He Tianyou's lover and liked He Tianyou, so it was entirely possible to commit perjury.