Some explanations...

[x-cyclops.livejournal.com]

... although I suspect a number of you have probably already guessed this, given that we don't generally make a habit of welcoming long-time associates of Magneto into the mansion.

Pietro Maximoff has been our source inside the Brotherhood for a couple of years now. He's provided us with a lot of critical information, generally at very critical times. It's thanks to him that we were able to rescue Lorna and Forge. Also, that mission at Christmas, where we destroyed that machine... that was more of a cover. Yes, it was good to get rid of it, but its destruction also covered Pietro delivering to me a list of emergent telepaths that his father was considering using to power a new Cerebro. I think we're all familiar enough with the Alkali Lake file to know why that would have been a very bad idea.

He fell out with his father over San Diego, and he's been on the run ever since. He didn't want to approach us until he was fairly sure that Magneto wasn't breathing down his neck wanting to kill him and anyone who offered him help.

I knew about this from the start, obviously - I'm the one he approached in the first place. The Professor knew from the start as well. Ororo knows, Alison knew... Wanda of course. I told Remy back while he was still doing intel for us, so Snow Valley probably knows now. But we had to keep the information relatively close, for obvious reasons.