Talk:Heavy Caliber/@comment-109.72.63.66-20141210160243/@comment-26027280-20150130203808

To the Tenno 2 posts up, the vaults show up in Orokin Derelict Exterminate not sure about any other ones but Exterminate vault runs are the easiet ones to do, but to get into the vault you need all 4 keys, which means you need a 4 person squad. There's another mission you can get the vault in, but I don't remember which one it is.