This is an idea I tried to play out a while ago, but it didnt get very far, so here goes.
Not long from now, researchers and scientists working a secret government facility were looking for a way to teleport to other parts of the world, or to other worlds. They activated a portal to a world with humans, orcs, elves, where magic was real. After several incursions, the project was shelved, but a powerfull warlord or mage using lord from there had his or her mages reactivate the portal, and other portals in other parts of the world.
They opened in various parts of the US, Canada, Russia, Europe, Mongolia. Humanity fought back, doing everything it could to limit the incursious, a true world-wide effort. A year on, a quarter of the land mass has been occupied.
My character would be a marine or army Captain whos company is defeated after a fight. Instead of being taken through the closest portal, I'm enslaved by one of the regional leaders, human or elvish, up to you. I would be dressed appropriately and kept as company, for bed sport.
If this idea appeals to anyone, let me know.