I'll say it now this MAY contain the smallest tiniest spoiler for the quest.

To anybody who has this quest do not bother unless you don't mind parting with THREE fusion cores to even be granted access to the Vault. Even if you did what i did and that's hand them to their overseer then kill the overseer to take them back YOU CANNOT kill their overseer she is invincible along with about 4 other NPC's in the Vault that will not stop attacking you.

Just thought i'd let you all know to save the hassle, however if you don't mind parting with three fusion cores go for it, in my eyes though with how rare they seem to be for me so far this isn't worth it. Especially with the reward their overseer gives you, only 100 caps for all 3, i'd say 1 fusion core is worth 1000 caps with how precious they are at least!

I rarely use the power armor. Unless I am forced too. Look like I should be saving the fusion cores.

I've found like 15 fusion cores so far, often in basemants of structures, also traders carry them from time to time in stacks.

Guys anything you think needs to be spoiler taged goes in the

section of the forum

http://www.gamesas.com/forum/326-fallout-4-cheats-spoilers-hints/

Pfft, three fusion cores. I just told em I was from another vault and they let me stroll right in.