You’re walking through the Mojave, everything is brown, dusty, and dead, and then you see it. A massive splash of green against the desert floor. It looks like paradise. It isn't. Honestly, Fallout New Vegas Vault 22 is probably the most stressful location in the entire game, and that’s saying a lot for a world filled with cazadores and deathclaws. It’s a literal deathtrap disguised as a botanical garden.
Most players stumble into this place because of a quest. Maybe you're looking for the HEPA 20 filters for the Brotherhood of Steel, or perhaps Thomas Hildern at Camp McCarran promised you a stack of caps to recover some "invaluable" research data. Whatever the reason, you walk through those big gear-shaped doors expecting some plants. What you get is a horror movie.
The Botanical Nightmare of Vault 22 Explained
The lore here is thick. It’s not just a "spooky plant place." Back before the bombs dropped, Vault-Tec designed this specific site to study "green" technologies. They wanted to see if they could create sustainable food sources for a post-nuclear world. They succeeded. Sorta.
The scientists experimented with pest control and high-yield crops. Specifically, they utilized a fungus known as Beauveria mordicans. In the real world, Beauveria is a genus of fungus that kills insects. In the Fallout universe, the Vault-Tec version was mutated. It didn't just kill pests; it started infecting the humans. It’s a classic sci-fi trope executed with brutal efficiency. The spores get into your lungs. They grow. Eventually, the host dies and becomes a "Spore Carrier."
Look at the walls. See that green moss? That's not just decoration. It’s the remains of the people who used to live there. It’s genuinely unsettling when you realize the "plants" you’re shooting used to be scientists, children, and maintenance workers.
Why the Spore Carriers are a Total Pain
If you’ve played the game, you know the jump scares are real. These guys hide in the foliage. One second you're looking at a patch of grass, the next, a humanoid creature is clawing at your face. They aren't particularly tanky, but they are fast.
The AI for these enemies is surprisingly effective for a game released in 2010. They use the environment. They wait. If you aren't spamming the VATS button every three seconds, you’re going to get jumped. It makes the exploration of Fallout New Vegas Vault 22 feel claustrophobic, despite the open levels.
Navigating the Green Hell
The layout is a mess. It’s five levels of broken elevators and locked doors. You start at the Entrance, move through Oxygen Recycling, Food Production, the Common Areas, and finally the Pest Control level.
- You'll need a decent Science skill or a very itchy trigger finger.
- The elevator is broken when you arrive. Fixing it requires a Repair skill of 50 or finding the parts. Honestly, just fix the elevator. Walking the stairs back and forth is a nightmare.
- Keep your eyes peeled for the "Overseer's Office." It's on the second level (Oxygen Recycling), but you need credentials to get into the deeper parts of the data banks.
There’s a specific vibe to the environmental storytelling here. You find terminal entries from a researcher named Keely. She’s one of the few who realized how bad things were getting. Reading her logs feels like watching a car crash in slow motion. She describes the coughing. The itchiness. The smell of wet dirt that won't go away.
The Big Moral Choice: To Burn or Not to Burn?
Eventually, you meet Keely. She’s still alive—somehow—and she’s determined to destroy the research. She knows that if this fungal data gets out into the Mojave, it’s game over for humanity. The plants would just eat the world.
Here’s where it gets tricky. Thomas Hildern—the guy back at McCarran—wants that data. He claims it’s the only way to save the NCR from a looming food shortage. He’s an arrogant jerk, but he might be right about the famine.
If you side with Keely, you have to help her vent gas into the vault and ignite it. This is a legendary "don't stand in the blast zone" moment. If you're standing in the wrong spot when you throw that grenade into the vents, you’re toast. Literally. Use the long-range detonator or just stand behind the heavy blast doors in the common area.
What Most People Miss in Vault 22
The "AER14 prototype" is the real prize. It’s a unique laser rifle that fires green beams instead of red. It’s tucked away in a common area behind a locked door (Lockpick 75). If you’re running an Energy Weapons build, this is non-negotiable. It has a higher crit chance and looks incredibly cool.
Also, don't ignore the mantises. They seem like low-level trash mobs, but in the tight corridors of the lower levels, they can swarm you. Use a flamer. Seriously. Everything in this vault is weak to fire. It’s the one place where the Incinerator actually feels like the best weapon in the game.
The Connection to Zion Canyon
A lot of players don't realize that the story of Fallout New Vegas Vault 22 doesn't end in the Mojave. If you play the Honest Hearts DLC, you find out where the survivors went. They didn't all die. A group escaped and fled to Zion.
But they brought the spores with them.
When you explore Zion, you find more Spore Carriers. You also find the journals of Randall Clark, the "Father in the Caves." He watched the Vault 22 survivors arrive. He saw them start to turn. He saw them start eating people. It adds a whole new layer of tragedy to the vault. These people weren't just "monsters"—they were desperate refugees who accidentally brought their own extinction with them in their lungs.
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Tactical Advice for Your Next Run
If you're planning to head in there, come prepared. Don't just wander in with a 10mm pistol and some hope.
- Bring Fire: Flamer, Incinerator, or even just a bunch of Shishkebab swings. The Spore Carriers and the plants have a massive weakness to fire damage.
- Cram and Purified Water: The radiation isn't the problem; it's the attrition. It’s a long crawl.
- VATS is your friend: Use it to scan the floor. If the red bar pops up in a patch of weeds, start shooting.
- Companions: Bringing Boone is a double-edged sword. He’ll headshot things before you see them, but he also tends to run into rooms and get surrounded. Lily or Rex might be better for the close-quarters combat.
The vault is a masterclass in how to do a "dungeon" in an RPG. It’s not just about killing things; it’s about the atmosphere. The buzzing of the lights, the rustling of leaves where there shouldn't be any wind, and the realization that the "Old World" was just as dangerous as the new one.
The NCR's hunger for the data in Vault 22 highlights one of the core themes of New Vegas: the tendency of humanity to repeat the same mistakes. They see a biological weapon and think "this could solve our lettuce problem." It’s ridiculous and terrifying all at once.
Actionable Steps for Completionists
To fully clear the Vault 22 content and maximize your rewards, follow this sequence. Start by grabbing the "There Stands the Grass" quest from Hildern at Camp McCarran. While you're there, talk to Angela Williams; she’ll give you a side objective to find Keely, which adds more context and a better reward path.
Once inside, prioritize fixing the elevator immediately. It requires a 50 Repair skill or finding the parts in the "Pest Control" level, but having it functional makes navigating the five floors significantly less frustrating. Go straight for the AER14 prototype on the fifth level (Pest Control) before you trigger the gas explosion, as the chaos of the final quest stage can make backtracking a pain.
When you finally meet Keely and decide the vault's fate, ensure you have a Science skill of 60 or higher if you want to keep the data and satisfy Keely’s moral concerns—this allows you to "trap" the data in a way that satisfies both quest outcomes if you play your cards right during the dialogue. Finally, head to Zion in the Honest Hearts DLC afterward to find the final journals of the survivors to truly wrap up the narrative arc of the infected researchers.
Don't forget to check the duffle bags near the entrance for basic supplies before leaving; the game usually tosses you a few stimpaks for surviving the ordeal. Exit through the main door, breathe the dusty Mojave air, and be glad nothing is growing in your chest.