When you are in the vault,be the age to take the g.o.a.t.,then talk to your dad a bit and look at the poem by the bone picture to the left,the poem is there but you need a lockpick skill of 50 the save gives you 2500 or something around that and some other stuff.ignore the safe for now.finish up the vault leave go to megaton go to cratersidesupplies and do all the quest.after your done,kill moria and the mercanery.check morias bodyfor the cratersidesupplies key,go behind the counter to the locker and you get everything she has including a lot of caps if you did all of the quests if no you will onley get about 1500 caps.now onto the safe in the vault,by now you would have tried to get in the vault right but you cant you need to be a bit past when your dad dies keeping the water purifer safe.(your dad dieng is a main quest)after that go back to the vault and go inside the wood.turn you radio on the vault emergancy system listen to amatas msg get in the vault.(if you dont hear the msg do a few more main quests and then you can go inside)look around for the safe in that room. and if your lockpick skill is not 50 you screwed up and will have to do this secret all over again.as soon as you find the safe lockpick if you dont know how to read the insturctions from the first time you lockpicked.get the caps do the quest in the vaults try not to kill the overseer if you do it doesnt matter amatas the overseer eather way.thats the end of the secret thanks for reading.