What episode did Wu Sidao analyze for Grandpa Four?

In the TV series Yongzheng Dynasty, Wu Sidao analyzed the situation for Grandpa Four in the 57th episode. After Wu Sidao finished speaking, Grandpa Four suddenly realized.

During the Yongzheng period, the fourth son, Wu Sidao, was a Yin Zhen man. He was brilliant, but he was jailed for making a scene in the examination room. His physical disability was treated as a VIP by Prince Yin Zhen of Yong. He doesn't live high in the temple, but he knows how far it is. He is a wise man, but he is a civilian who knows the emperor's mind.

In fact, Wu Sidao was familiar with the power allocation of the Qing court and was able to use all kinds of political resources flexibly. He is good at reading Kangxi's mind to ensure that Yin Zhen can go one step ahead in the struggle to seize power. Without Wu Sidao of Yongzheng Dynasty, everything would be stiff, thin and dull.