The Portal Project followed in the wake of Princess Twilight's misadventure into one of the worlds of the humans. The brightest ponies from across Equestria created new portals to fantastic worlds, and humans became merely a common encounter in the various expeditions. There were less than successful moments in this age of discovery, however. Hostility and violence sometimes waited through the portals, and ponies were lost.

Some worlds were much darker than others. Most would kill a pony outright, but others would snatch them up in a whirlwind of bloodshed, pull them screaming into the damnation, and ponies would come out changed- if they came back at all. Some did not, which for their families and friends, was probably for the best.