Graphics card manufacturer Nvidia has created a new mod for Fallout 4—named Vault 1080 and said to “pack a serious technological punch.”

Developed over the last six months by the company’s internal team Lightspeed Studio, Vault 1080 is similar in size to the other vaults found scattered throughout the main game, and comes with its own brand new quest line. It’s due to launch tomorrow, September 2.

So what’s it all about? It’s Fallout as we’ve never seen it before, we’re told, and leans heavily on volumetric lighting, “in ways not seen in the standard game”. It also delivers more realistic shadows and textures courtesy of HBAO+—a technique which improves existing ambient occlusion.

Story-wise, Nvidia’s Steve Williams best describes it like this:

“It’s a dark and ominous journey before you even head below ground, as you travel to the ruins of a fog-shrouded church through hostile marshland. Once in you find the entrance to Vault 1080 and its dark, intimidating tunnels. Tunnels that are, inevitably, full of twisted dangers.

“It’s certainly taken its toll on its occupants. They’ve become a congregation that embraces the darkness and sickness, and they’ve done it—so they believe—to survive. They’re not the friendliest bunch. But is the whole thing built on lies? The truth is deep within Vault 1080, through a whole lot of fearful mystery. Find it and decide for yourself whether the monsters deserve their salvation… or not.”

Nvidia's Fallout 4 Vault 1080 mod is out tomorrow. Head over to the Bethesda site to download it when it becomes available.