Vault 22 Vault 22 is a Vault - Tec Vault constructed before the start of the Great War in 2077 in what became the Mojave Wasteland . The Vault door is open , with various kinds of plants around the exterior and creatures such as . It is located , and can be approached from south - south - west of the Griffin Wares sacked caravan , east of Jacobstown and west from The Thorn . The entrance is at the bottom of the cliff . Background . Vault 22 was a “ green ” vault , filled with scientists dedicated to their experiment : keeping the entire population of the vault alive with plants grown within its confines . Upon entering the vault scientists brought three live species with them to study ; the common mantis , a similar to the Venus fly trap and the " Beauveria mordicana " fungus designed at Big MT to kill the most common pests . It was this fungus that would eventually lead to the demise of the vault as its spores proved toxic and mutagenic to humans , and turned the vault ' s inhabitants into spore carriers . Many prospectors and mercenaries have attempted to locate the data the scientists left behind , but so far nobody has returned alive . The vault is open , but warning signs left outside the vault by people lucky enough to survive their initial encounter with the vault ' s inhabitants warn that " the plants kill " and one should not venture inside . Leaving the Vault . At some stage after the mutagen began to infect other Vault dwellers , prior to 2096 , a group of around 118 Vault 22 dwellers evacuated the vault and made their way to Zion Canyon on an expedition to explore the region as a possible area to settle . Many of these Vault dwellers had already been infected by the mutagen which killed off most of Vault 22 , leaving many of these Vault dwellers suffering similar symptoms , most notably , according to Randall Clark ' s terminal entries , the racking cough . Several of them met their ends at the hands of the experimental mutagen , which eventually turned them into spore carriers ; those that survived were systematically wiped out by Randall Clark due to their cannibalistic ways - many terminal entries by Clark claim that the Vault dwellers captured , murdered and then ate the flesh of a number of survivors residing in Zion . After eleven months living in Zion , the remaining thirty - four Vault 22 dwellers elected J . Hendricks to be the Overseer . His first order as Overseer was to move out of Zion Canyon . On February 2096 , they all moved south - east out of Zion . What happened to the survivors is unknown . A single member of the expedition left the group as they evacuated Zion , eventually being caught in one of Randall Clark ' s many traps . Clark found and almost finished the injured Vault dweller off , only to find himself feeling sorry for her . He rescued and nursed the survivor , called Sylvie , back to health . They eventually became a couple and Sylvie wound up becoming pregnant . Sadly , however , Sylvie and the unborn child died during childbirth . Layout . The entrance of this vault is quite unusual . It is advertised with a sign that reads " Welcome to Vault 22 " covered by graffiti which says " Stay out ! The plants kill ! " The vault door leads directly outside , unlike most that have a natural rock formation or tunnel enclosing the entrance . Once inside the Vault , the Courier will come to a door that leads to a room with an elevator and stairs . From here on out , the player will encounter spore carrier s , , and throughout the Vault . The vault is split into five levels , the different floors can be accessed by repairing the main elevator within the Vault ( requires Repair skill of 50 ) or accessed by perpendicular staircases . 1st floor - Entrance Hall . Immediately upon entering the vault , turn to the left to find a usable mattress , a duffle bag with some supplies , and one of Keely ' s terminals with entries 1 and 2 . Next to the mattress , hidden between two books , is a " Programmer ' s Digest " . 2nd floor - Oxygen Recycling . From the entrance of the lab take a right and continue to the room directly across the hall to find one of Keely ' s terminals with entries 3 , 4 , and 5 in the series . 3rd floor - Food Production . The keycard to access the cave tunnels on level 4 is located in the Common Quarters ( the floor below ) . Once inside , an average locked door must be opened on the lower level in the northwestern corner of the room or you can go to the overseer ' s office , go onto the terminal and disengage the lock . Once inside , the first room on the left , on a shelving unit will have the Vault 22 cave door keycard . Note that the keycard does not open the cave door on level 3 directly , it instructs the terminal next to the cave door to unlock the door . From the elevator , go down to the hallway and into the first room on the right to find one of Keely ' s terminals with entries 6 and 7 in the series . For the quest Bleed Me Dry , the pile of giant mantis egg ( s ) will spawn in the caverns down a side tunnel guarded by a giant mantis female and several giant mantis nymphs . 4th floor - Common Areas . From the entrance to the Commons , take a right over the little bridge and straight back to the billiard room for one of Keely ' s terminals with entries 8 and 9 in the series . The keycard that unlocks the door to the tunnels on the Food production level is found in the lower level of the Common Areas in the Quarters section on a shelf in the first room to the left . If the keycard cannot be found , check the floor near the shelf , as it may have somehow fallen off . It is a darkish red / orange color . The stair between this level and the fifth level is blocked by debris . The tunnels on the third level or the elevator can be used to bypass it . A flamer and several cans of fuel can be found in the room across from the room with the terminal that talks about Dr . Peter ' s re - animation . 5th floor - Pest Control . This floor is filled with deadly " Savage " spore carriers . The large cavern contains many giant mantises and spore plants . Five mantis ootheca and Keely are located here , in an alcove on the far end of the cavern . Appearances . Vault 22 appears in " " and is mentioned in the " Honest Hearts " .