In May 1935, Red Army commander Liu Bocheng was trapped: enemies behind him, and ahead, a Yi ethnic community whose language and customs his troops did not understand.

The Yi are one of China's many ethnic minorities, with their own language and traditions. Decades of conflict had left many Yi deeply suspicious of outside armies.

Rather than fight, Liu chose trust. He and Yi chieftain Xiao Yedan swore brotherhood – lake water as wine, one bowl between them. The rule: respect Yi customs, pay fair for everything. Sincerity won hearts. Yi villagers guided the troops, shared food, some even joined their ranks.

Today, the lake is still. New Yi villages thrive. And the story still passes from elders to children.