Never Split The Party

There are nine known realms, a world for each race, including dwarves, gnomes, and elves. In the middle rests Middang3ard. Each world knows the others. Each, except Earth. Humans turned their backs on magic, throwing their stock into science and technology, their governments shielding the people from the reality of what was going on elsewhere. Then the Dark One appeared, threatening to overrun the nine worlds, starting with Middang3ard and ending with Earth. Now, humans must send elite warriors to Middang3ard to fight, else humans will fight their own lands when the Dark One invades Earth.