GSC Game World, the original creator of the STALKER game franchise, has unceremoniously announced a sequel. Called STALKER 2, the game is scheduled to launch sometime in 2021, according to its website.

The original STALKER: Shadow of Chernobyl is set in the area around the titular Soviet-era nuclear power plant, which experienced a critical meltdown in 1986 that blanketed parts of Ukraine in nuclear fallout. Released in 2007, the critically acclaimed first-person shooter is considered to be the progenitor of the modern open-world sandbox genre. Shadow of Chernobyl spawned a few follow-up titles, namely STALKER: Clear Sky in 2008 and STALKER: Call of Pripyat in 2010.

In 2011, founder Sergiy Grygorovych shut GSC down. The move stopped cold the progress on a fourth game in the series, and left many skilled developers in the lurch. From Polygon’s 2013 feature story:

In February of 2011, while Grigorovich and his team were busy working on the fourth game in the series, called STALKER 2, Ernst & Young, a multinational financial services firm, named Grigorovich Ukraine’s entrepreneur of the year. He was the first member of Ukraine’s booming IT industry to earn the honor. Ten months later, on Dec. 9, Grigorovich dissolved his company. He gave no explanation to the staff beyond “personal reasons.” While the games media flailed for answers, Ukrainian news site Ukranews posted the simple headline, “Kiev company ... decided to self-destruct.”

In 2015, GSC suddenly sprung to life. In one breath it condemned an unsanctioned effort to crowdfund a successor game, and with the other it announced a new real-time strategy title called Cossacks 3. Since then it’s been relatively quiet.

guess the engine, lol — Sergey Galyonkin (@galyonkin) May 15, 2018

News comes by way of Sergey Galyonkin, an employee of Epic Games and the creator of the SteamSpy service. In a Tweet, Galyonkin seems to be indicating that GSC has licensed Epic’s Unreal Engine 4 to create its next game.

The STALKER 2 website does not mention any platforms; all the existing entries in the franchise were released on Windows PC. Polygon has reached out to GSC and Galyonkin for more details.