Overwatch is going to the moon with a brand new assault map, available to play on the PC’s public test region today.

Horizon Lunar Colony joins Hanamura, Temple of Anubis, and Volskaya Industries as the fourth assault-style map in Overwatch. Attacking and defending teams battle for control in the scientific moon base, witnessing the fate of the colony that lost contact with Earth years ago.

During a developer update video, Overwatch game director Jeff Kaplan mentioned that there will be a small portion of the map outside the lunar colony. That means low gravity, a first for Overwatch.

The Horizon Lunar Colony was the home of the hero Winston before he escaped. It’s humanity’s first step into colonizing space and acts as a test for how humans and gorillas respond to living in extraterrestrial conditions.

The gorillas in the Horizon Lunar Colony were subject to genetic enhancement tests that increased their intelligence but also made most of the angry. The gorillas led an uprising against the resident scientists to take control of the facility (which is when Winston escaped on a homemade rocketship).

In Monday’s tease of the Horizon Lunar Colony map, Blizzard gave an update on what’s been going on in the colony. It appears that most of the gorillas were sequestered to their quarters but two gorillas were unaccounted for: Winston (we know where he went) and Hammond.

At an Overwatch anniversary event in New York City this month, Overwatch game director Jeff Kaplan said that Overwatch‘s maps are used as a tool for storytelling in the Overwatch universe, hinting that more story-related information would be contained inside future maps.

“The maps we have planned for release later this year are heavily story-driven,” Kaplan said.

Horizon Lunar Colony will likely contain clues to Winston’s past and possibly some information about other Overwatch heroes or the universe at large.

In the past, deep investigations of maps led to the discovery of Sombra before her release, so there may be hints at a future Overwatch hero within Horizon Lunar Colony.

The map does not have a scheduled release date for normal servers on PC, PlayStation 4, or Xbox One. To access it on PC in the meantime, select the public test region on the region drop down menu in the Overwatch section of the Blizzard app. Make sure the version is up to date before you run the game in the PTR.

If you don’t have Overwatch for the PC, you can enjoy the rest of these photos and rest assured that the map will get a full release soon.