Celestia and Luna are two familiar figures. What people of their realm don't realize is that there are two other realms, which are supposed to help the Overworld. Heaven and Hell. Who's in charge there? None other than their brothers. Only having recently gained access to the Overworld, they show up, forgotten by Celestia and Luna's citizens. However, one of the brothers, the Prince of Hell, has been missing for three thousand years. Strangely, he doesn't remember any of it... but he's shown up in Overworld, having recently made friends with Twilight Sparkle and her friends. He doesn't even know who he is, but he's going to find out soon enough.