This is an episode from the Three Kingdoms period. Zhou Yu ordered Zhuge Liang to produce 100,000 arrows within ten days. Zhuge Liang surprisingly requested only three days and signed a pledge, accepting punishment for failure. Zhou Yu ridiculed him and secretly ordered his troops to withhold materials, while sending Lu Su to spy.
Zhuge Liang, aware of the plot, asked Lu Su for help. He requested 20 boats, each lined with straw scarecrows and manned by 30 soldiers, and swore Lu Su to secrecy. For two days, nothing seemed to happen.
In the early hours of the third day, Zhuge Liang invited Lu Su for a boat ride. The boats, tied together, sailed toward Cao Cao's camp in a thick river mist. As they neared the enemy camp before dawn, Zhuge Liang ordered his soldiers to shout and beat drums, simulating an attack, while he and Lu Su calmly drank wine inside a boat.
Mistaking the noise for a surprise attack, Cao Cao's forces, unable to see through the fog, ordered 3,000 archers to shoot toward the sound. The straw scarecrows were quickly filled with arrows on one side. Zhuge Liang then had the fleet turn to expose the other side. By daybreak, both sides were covered. Zhuge Liang ordered a return, with soldiers shouting, "Thank you, Cao Cao, for your arrows!" They collected over 100,000 arrows upon return.