You help the remnants of the Enclave and they help you in the final battle against the Legion. In the aftermath, when the dust has settled and the fighting is over, you're standing there with the NCR cheering their victory and
the Enclave members standing around. When the higher-ups of the NCR find out about the Enclave helping they lambaste them for the "crimes of the past" and order some nearby soldiers to arrest them. Many of the soldiers
recognize and appreciate what the Enclave remnants did to help and refuse to go through with the order. One of the Generals, maybe one who was wronged in the past by the Enclave, pulls out his gun and shoots one of
the remnants and kills him. Some stand around confused, and some are abhorred by this display and throw down their weapons and walk over to the Enclave remnants and offer to join them. With some discussion, the
Enclave members, angered after seeing their companion killed, agree and they leave the area with their new "recruits." Thus, you have the rise of a new Enclave. This leads to the next chapter in FO and the Enclave
reignites a war with the NCR, who tries to stamp out the Enclave for good. Over time, the new Enclave, not as merciless as the past version, starts to turn into what the NCR could have been and begins winning the
hearts and minds of the former nation's people and grows very quickly, especially with the Legion decimated and really not a factor anymore.

You could go in many directions with this...

Please no, we already have a chapter in Chicago and remanants in Capital Wasteland.
We really don't need any more Enclave let alone the "rebirth" of Enclave.

No, I really don't
want a
Broken Steel kind of
DLC.

The ncr should have killed them for what they did before

Wow, poetic :vaultboy:

Anyway, I agree. No more Broken Steel, and no more Enclave. I like some remnants scattered about like in NV, but a "new Enclave" would be very bad.

The Enclave is a dry well, at this point, any story involving a powerful Enclave would feel like you're scrapping moss from said dry well.