Another World? We'll Take It

The Blue Planet is dying and Jasper finds he can cross into another world, one with elves, dwarves and orcs, where humans with black hair and black eyes sit at the bottom of everything and are bullied openly. He does not keep the discovery to himself. He hands the crossing over to the sanctuary authorities, and then goes back through with a modern army behind him. Dwarven steam engineering is the height of the other world's technology and it does not survive contact with modern steel and modern weapons. The elves have been running schemes for a long time and he pulls them into the open. The demon race is the thing all of them have avoided naming, and Jasper works to get elves, dwarves, orcs and humans onto the same side against it, arguing for the standing of black-haired humans in the process. Magic and steel meet on the same ground, and the war changes what is possible on both his dying planet and the world he opened.