On March 18, 2014, Kojima Productions and Konami released Metal Gear Solid V: Ground Zeroes. The game served as a prelude to the much larger The Phantom Pain, which launched more than a year later to its own string of controversies. At Ground Zeroes’ release, gamers knew they were immersing themselves in a sort of prologue and Metal Gear Solid tech demo that showed off some of the mechanics to be expected in the completed 2015 release. What the public didn’t know at the time, however, was that they were also playing through the preamble to Konami’s latest Metal Gear entry: Metal Gear Survive.

The zombie-survival, action-adventure base builder may take place in an alternate version of the Metal Gear Solid V world, but covers much of the same terrain, utilizing maps and locations from The Phantom Pain. Think of it as The Cloverfield Paradox of the Metal Gear series.

Metal Gear Survive picks up at the end of Ground Zeroes, when (SPOILER ALERT) Big Boss and Kazuhira Miller are forced to flee the destroyed offshore Mother Base. Amidst the destruction, many of Big Boss’ Militaires Sans Frontières soldiers are sucked up into wormholes that open randomly and sent into a different dimension filled with pointy-headed, crystalline zombies. Thus, launching the strange events of Metal Gear Survive.

Metal Gear Survive is far from the first title in the series to deviate from the series’ main canon to focus on characters beyond the main cast of Metal Gear Solid. In 2013, Platinum Games and Kojima Productions released Metal Gear Rising: Revengeance, which strictly followed former FOXHOUND operative turn cybernetic ninja, Raiden, who made his unexpected debut in Sons of Liberty. Though the events of the Metal Gear Solid and Solid Snake are alluded to in Revengeance, the game ultimately follows its own path.

Considering Kiefer Sutherland and none of The Phantom Pain cast has reportedly signed on to Survive, chances are Konami’s latest Metal Gear will take the same route as Revengeance, creating its own lore within the Metal Gear Solid universe. Whether the game’s ending will link back up to The Phantom Pain or any part of the Metal Gear Solid timeline is unknown, but the likelihood is slim.