Why didn't Greer stay at Sanyushu?

In order to enable Gao Zhihang, Greer left Li Liang.

The TV series tells the story of 1929 that Gao Zhihang, an aviation officer of the Northeast Army, was sent to Heihe by General Zhang Xueliang in exchange for a Japanese plane shot down by bandits in Qingshan a few days ago. Gao Zhihang accomplished the task brilliantly and met Greer, a Russian beauty, in Heihe. Greer was deeply attracted by this French pilot with a background of studying in France and went to Shenyang with him regardless.

After the September 18th Incident, Gao Zhihang volunteered to resist Japan. Although Zhang Xueliang was caught in the whirlpool of resistance, he still recommended Gao Zhihang to join the national army and settle in Hangzhou Jianqiao Airport.

Greer and Gao Zhihang had to choose a divorce because the Air Force banned pilots from having foreign spouses. Greer returned to his hometown of Tonghua, Gao Zhihang, bid farewell to his in-laws, and set foot on the road of drift from place to place alone, and never heard from him again. The eldest daughter, Li Liang, later asked people to inquire about her biological mother in Heihe and other places, but there was no news. Greer became an eternal mystery. Ye Rongran, the granddaughter of the great industrialist, admired Gao Zhihang and they had a crush on him.

When the Battle of Songhu broke out, the 19th Route Army of the National Army bravely resisted the Japanese invaders, and Gao Zhihang's Eagle Air Force was ordered to take off to meet Japanese planes. The air battle between Shanghai and Shanghai shook the whole world. China Air Force defeated Japanese Air Force with weak strength, creating a miracle in the history of world air combat. Gao Zhihang and the Hawks became national heroes.