Once the enemies attack your castle, it will start to burn, and the defense points will gradually decrease during the fire.
 The fire will last for a while. Once the defense points of the city wall drop to 0, the castle will be relocated to another place on the battlefield.

 To put out the fire, click on the city wall, then city wall construction, and use the fire extinguishing to end the fire immediately.
 You can also restore the city's defense points to protect your city.