That Time I Got Reincarnated as a Slime, Vol. 12 (Light Novel): Volume 12

THE GEARS OF WAR BEGIN TO TURN Threatened by Tempest's continued rapid expansion, the Eastern Empire finally starts setting the stage for all-out war with the monster nation. According to Chloe, the time-traveling Hero, there exists a timeline in which the Empire kills Rimuru and Tempest subsequently collapses. While Rimuru's doom isn't set in stone, his victory isn't a foregone conclusion either. This may be a different timeline, but the slime demon lord nonetheless steps up his guard-and just as he does, several Imperial spies infiltrate Tempest...