Cloud (a tom) and Storm (his twin sister) are orphans. Their parents, Mist and Lighting, as well as their little sister, Sky, were killed in a fight when an invading army attacked their home. The army won, and is now in power. Cloud and Storm escaped and joined a rebellion against the army. Cloud is a spy, it's his job to find out information on troop formation and what not. Storm's the assassin. Once Cloud gives her the info, Storm must kill important cats to delay attacks and give the rest of the rebellion time to prepare. Cloud was discovered and held prisoner. Storm tried to rescue him but got captured as well. They were publicly executed as an example, but even so, the rebellion won one month later due to information Cloud and Storm provided, and they are now immortalized as heroes.
Credit to @Moonflight_358 for the CC line art. I tried.
