So, first, sorry for my Bad English... i'll try my best ^^

Early in Game, i discovered Hidden Valley, the Bunker of the Brotherhood of Steel.

I like them. In Every Game, i want to be a part of them. So i helped them. I decided to get Hardin as Elder of BoS instead of McNamara, and after that i was doing more quest's in the mojave.

After Day's of Playing, i came to the End. Then, I got a Quest to take care of the Brotherhood. Oh What? I walked back to Hidden Valley, Talked to Hardin.... And... There is NO WAS to rescue them !? WTF? Why ?

I've read that if McNamara was Elder, i can have Peace between NCR and BoS... but why not with Hardin ? Is there ANY Way i can save them?
It's not fair ! Nobody told me that i have to let McNamara as Elder, and so i Played Day's for Nothing *cry*

There's nothing you can do. Kill the BoS and you can ally with them in another playthrough.

Killing them is pretty much the only way to stock up on PA too. I felt bad at first and killed house. But then I felt bad about that and decided the loot would be worth it. If your science is high enough you can disable the turrents which will make looting easier, otherwise they kill you quick. Then I just stole that super sledge and started hacking away. Had to make a few trips cause PA is heavy and my followers couldn't carry faction armor.