Blizzard quietly had World of Warcraft Dragonflight players test run an upcoming The War Within feature without telling them.

Zaralek Cavern, which arrived last May in patch 10.1, lets you explore the zone underneath Dragonflight's main landmass at a scale never done before in the MMO. It works sort of like Elden Ring's underground areas except it's fully accessible without loading screens or long elevator rides. You can dip down there to finish some quests and leave whenever you like.

In a recent group interview with PC Gamer, game director Ion Hazzikostas said, “Zaralek Cavern was a little bit of a test run for something we were planning, as is now pretty obvious.”

While the first phase of the War Within alpha build going live this week only has the surface-level intro zone available, the influence of Zaralek Cavern is already apparent. In the first Delve, flexible mini dungeons new to the expansion, you battle through small caves with a buddy just like some of the activities in Zaralek. There's a short quest to finish and some new hazards to avoid, like a knock to your health in dark areas, but the overall aesthetic is very close to what we saw in Dragonflight.

I expect the Zaralek similarities to be even more obvious in later zones like Hallowfall, which takes place entirely underground. One of WoW's oldest races, the bug-like Nerubians, live down there and will be one of the expansion's primary antagonists. In the few screenshots and bits of footage we've seen, Hallowfall is huge, colorful, and barely feels like it's deep below the surface. There's even enough room to fly your mounts down there—something that was also possible in Zaralek Cavern.

“15 years ago, the fact we didn't do more to explore the Nerubian part of Northrend [in the Wrath of the Lich King expansion] was a source of disappointment,” Hazzikostas said. “It's something we knew that we wanted to revisit, telling the story of an expansion that delves beneath the surface of the earth felt like a very natural time to really double down on that.”

You won't be able to go underground quite yet in The War Within alpha. Blizzard wants to focus on getting feedback from the intro experience, but it plans to add more zones in future phases as it did with the Dragonflight alpha. Hallowfall is surely on its way, so grab your helmet and axe because we're all subterranean exterminators now.