Stranger Thingshas become one of Netflix’s biggest shows, with the series earning critical-acclaim and spawning a franchise of its own that has seen it expand to books, video games, and more. And now, with the highly-anticipated third season ofStranger Thingsset to kick off on July 4, a crossover event has started in the popular battle royale gameFortnite.

The full scope of theStranger Things/Fortnitecrossover is unknown at this point, but it will likely shift into full gear when the new season premieres on July 4. In the meantime, portals to the Upside Down - an alternate universe inhabited by monsters in the show - have started appearing at various locations on theFortnitebattle royale map.

TheseStranger ThingsUpside Down portals seem to appear mostly inside buildings. Players are free to go through them, though they don’t actually end up in the Upside Down when they do so. Instead they are simply teleported to a different Upside Down portal elsewhere on the map.

TheStranger Things/Fortnitecrossoverwas first announced a few weeks ago, but further details on it are still unavailable at this time. If it’s anything like the other crossover events inFortnite, then it will likely feature some limited-time cosmetics for players to unlock, as well as aStranger Thingsgame mode and special challenges.

In the meantime, playing theStranger Thingscontent inFortniteisn’t the only way fans of the show can experience the world of Hawkins, Indiana in video game form. Releasing tomorrow alongside the show isStranger Things 3: The Game, which is a retro-style beat ‘em up.

With the success of theAvengersandJohn Wickcrossoverevents, it’s no surprise thatFortniteis crossing over with other popular franchises as well. Just how extensive thisStranger Thingscrossover event is remains to be seen, but more should come to light in the coming days.

Fortniteis out now in early access for Android, iOS, PC, PS4, Switch, and Xbox One.