The Goblin Reservation

Earth in the distant future. Humanity has scattered throughout the cosmos, and its native planet has turned into a training center. And to keep the students from getting bored, nature reserves for fairy-tale creatures were set up nearby: goblins, gnomes, and trolls.
Not life, but a fairy tale! There’s also a chance to bring a genius from the past—say, Shakespeare—and talk with him. In general, there are no problems with intellectual entertainment.
But there wouldn’t be problems beyond that—until aliens decide they want an artifact taken by humans from our distant past. That’s when everything starts to spin.