That time I got reincarnated as a slime

"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 susbsequently 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 demon slime nonetheless steps up his guard--and just as he does, several imperial spies infiltrate Tempest"--Back cover.