1) Yehoshua sent spies to scout out Ai and they reported it was a small city with few people. 2) In the initial battle against Ai, the Israelites were defeated and lost 36 men. 3) It was revealed that Achan had stolen valuables from Jericho in disobedience, which had brought God's wrath upon them. Achan was executed for his wrongdoing. 4) Yehoshua devised a new plan to ambush Ai by hiding soldiers nearby and drawing their army out of the city with a feigned retreat, allowing the other soldiers to enter and capture the now empty city.