What is the name of the sad background music in Princess Zhu Huan Part III?

Which episode is it? I just watched it once yesterday, and I know the background music after a few episodes.

These are all the songs

Heaven and Earth (theme song) Singing: Ku Kuiji

As long as you sing (theme song): Ku Kuiqi, Crystal, Zhou Jie, Ma Yili, Tamia Liu, Huang Xiaoming.

Singing at this parting moment (ending song): Ku Kuiji

How to do it (ending song) Singing: Liu Pan

After your farewell (ending song), sing: Chen Sisi

Ask Yaner (ending song) Singing: Ku Kuiji

Heaven and Earth Meet (Episode) Singing: Liu Pan

Mountain Tour, Water Tour (Episode) Singing: Chen Sisi

Reunion Moment (Episode) Singing: Liu Pan

Most afraid of parting (episode) Singing: Liu Pan

Small Bridge Flowing Water (Episode) Singing: Chen Sisi West Lake Willow (Episode) Singing: Chen Sisi

If you want to say that you are sad, it is probably when you leave (that is, when Erkang died) to meet with heaven and earth. Wei Zisang)