In the 25th century AD, the moon is no longer a distant satellite, but the last "star shield" for earth civilization to resist unknown threats. In orbit around the moon, giant space stations and unmanned defense satellites are densely populated, while countless orbital gun arrays and particle shield generators stand on the surface of the moon, closely guarded by the elite "Moon Guards". Zhao Yi, the young commander of the Tranquility Zone Fortress, has distinguished himself among the Guards with his calmness, determination and excellent tactical abilities. However, when an unprecedented "super-invisible invader" quietly approaches the moon, all detection systems are ineffective, but the orders within the Earth Federation are lagging behind due to political corruption. In an isolated and helpless situation, Zhao Yi must activate the "forbidden weapons" hidden deep in the fortress and lead his men to resist this unprecedented invasion.
