How to Get the TNT Dome Key 2 and the Fusion Mag Plan-Fallout 76

TNT Dome #2 sits southeast of Black Mountain Ordnance Works, locked behind a special key. Inside, you'll find the Plan: Alien Blaster Fusion Mag and some Alien Blaster Rounds. Learning the plan lets you craft a Fusion Mag for the Alien Blaster, switching the weapon to Fusion Cells for ammunition. Getting into TNT Dome #2 requires finishing a hidden quest. The TNT Dome Key 2 won't drop from nearby enemies or containers—instead, you have to visit several locations and pick up the required items in order. The game gives no formal quest markers, so knowing the steps ahead of time saves a lot of searching.

Is the Fusion Mag Plan Worth Getting?

The Plan: Alien Blaster Fusion Mag does one main thing: it unlocks the Fusion Mag mod for the Alien Blaster. Once installed, the Alien Blaster can run on Fusion Cells, which are far more common and easier to keep stocked. The mod is not a straight upgrade, though. According to game data, installing the Fusion Mag affects the Alien Blaster's base damage and magazine capacity. The mod suits players who want to switch ammo types, or who plan to use Fusion Cells over the long term. If your goal is simply to own an Alien Blaster or complete the collection, the weapon itself is enough—you don't need to chase down the TNT Dome Key 2 at all. Before entering the dome, bring radiation protection and items that remove or resist radiation, since the dome sits in a high-radiation area.

Rusted Key

Start at Graninger Farm in the Toxic Valley. From there, head toward the butterfly marker on the map, where you'll spot a run-down building near the toxic pond. Go inside and check the safe—you'll find the Alien Blaster and the Rusted Key inside. The Rusted Key blends in with the other items in the safe, so look closely. If the key isn't there, another player has likely already picked it up; switch servers and check again. Once you have the Rusted Key, move on to the next location.

Freddy Fear's House of Scares

Next, travel to Freddy Fear's House of Scares in the Mire. Go inside, head up to the roof, and find the red door on the right side. Use the Rusted Key to unlock it, then look under the desk for a holotape called Stolen Terminal Passcode. This holotape is required for the steps ahead, so keep it in your inventory.

Shadowbreeze Apartments

After that, head to Shadowbreeze Apartments in Morgantown. Use the scaffolding outside to reach the second-floor balcony, then make your way to the top of the building. Use the terminal on the top floor, read the top two entries, and choose the option to write the access code onto the holotape. If the terminal won't complete the write, someone on that server has likely already done this step—switch servers or enter a private world and try again. Once the code is written, take the holotape to Pleasant Valley Cabins.

Pleasant Valley Cabins

Travel to Pleasant Valley Cabins in the Savage Divide and enter the large cabin on the north side of the area. Head to the bedroom and use the terminal there. The terminal shows a one-time code—write it down, since you'll need it to open the safe. The TNT Dome Key 2 is not in the terminal. Once you have the code, go from the bedroom through the lounge to the balcony, drop through the gap in the railing, and land on the rocky ledge beneath the cabin. Follow the rock face along the base of the building, pass through a gap in the rocks, and near the brick wall you'll find a hidden wall safe. Enter the code from the terminal to open the safe and collect the TNT Dome Key 2.

Things to Keep in Mind

Rusted Key: Found in the safe inside the Graninger Farm building. If it's missing, switch servers.

Stolen Terminal Passcode: Found at Freddy Fear's House of Scares. You'll later write the access code onto it at the Shadowbreeze Apartments terminal.

Writing the access code: If the terminal won't finish the action, switch servers or enter a private world and try again.

Hidden safe: Located in the rock face beneath the Pleasant Valley Cabins cabin—not inside the building. Drop through the balcony railing gap to reach it.

Entering TNT Dome #2 and Getting the Plan

Once you have the TNT Dome Key 2, return to Black Mountain Ordnance Works. Follow the road south, turn left at the T-junction, then continue east to find TNT Dome #2. Use the TNT Dome Key 2 to open the entrance and step inside. Inside TNT Dome #2, you'll find the Plan: Alien Blaster Fusion Mag on the table, with Alien Blaster Rounds nearby. Learn the plan, and you can craft the Fusion Mag for the Alien Blaster at a weapons workbench.

The full route is: Graninger Farm → Freddy Fear's House of Scares → Shadowbreeze Apartments → Pleasant Valley Cabins → TNT Dome #2.

For your first run, bring radiation protection, Rad-X, and RadAway. If a required item doesn't appear, switch servers and check again first. Once everything is done, you'll have the TNT Dome Key 2 and the Plan: Alien Blaster Fusion Mag. The Fusion Mag makes the Alien Blaster use Fusion Cells, but it also changes the weapon's damage and magazine capacity. Whether to install the mod depends on how you plan to use the weapon.