In ancient China, the Wei and Wu kingdoms joined together to fight against the Wei Kingdom. 

Zhou Yu, the chief military commander of the Wu Kingdom, ordered Zhuge Liang (the chief minister of the Shu Kingdom and generally regarded as the kingdom's top master-mind) to produce 100,000 arrows within 3 days.  Zhuge Liang also agreed to be punished if he failed to complete the order

Zhou mocked that Zhuge was looking for self-destruction. On the one hand, Zhou ordered his troops not to provide Zhu with materials to make the arrows. He also sent Lu Su to see how Zhuge was dealing the problem.

Zhuge had already realized that this was a plot. He asked Lu (who was kind-hearted) to lend him 20 boats, each lined with straw scarecrows and manned by 30 soldiers. He also requested that Lu not tell Zhou what was happening.