From the rec.arts.comics.xbooks Frequently Asked Questions list:

--- What is this Kid Dynamo thing? Where can I find it?

Kid Dynamo is a fan-fiction written by once-netter Connie Hirsch, which deals with the New Mutants in the days just after Magneto took over the School (right after New Mutants #52). A very good story by any standards, most people who have read it have granted it automatic status in official Marvel history, vastly preferring it to the eventual rise of Cable and the appearance of X-Force, or at least delaying that inevitable occurence by including Kid Dynamo.

Here is a site that links to all the chapters.

I feel constrained to assert that the narrator is not a Mary Sue, I mean, aside from the obvious facts that she does not have ravishing red hair or a great singing voice, she's like way too angsty and neurotic to be perfect. Also there's that problem with the unreliable narration....

There really is quite a bit of pre-NM#52 Magneto here too.

Dang, Connie. I've just read the first two chapters and I'm ready to propose marriage. This is great.

t bounces around like a praised hyperactive puppy on methedrine

Wow, Connie, how did I not know about this? Very impressive.

Connie, that rocks the house, woman.

A very good story by any standards, most people who have read it have granted it automatic status in official Marvel history,

::blinks::

Rock ON, Connie. That's wicked fucking cool. Go you!

I thought I would quote that, because it's not just me being all boostery about my story. :-)

Aha! I was so sure I wasn't supposed to read it, because it's not, you know, officially archived. I bothered my semi-lurker friend Snacky, who had it on her hard drive, and she also linked me to the sooper sekrit unofficial archive. Which, um, not so secret.

It was reading that story that I realized how little XMen comics canon I know. Didn't all come through in the animated series, you know?

And I found myself in conversation elsewhere with a very nice woman called Ayelet Waldman, who writes mysteries, and we were chatting away and it turns out she's married to MICHAEL CHABON!

Chabon's a pretty nice guy himself. I used to manage a bookstore, and I worked the release party for Wonder Boys. Later, the day after he won the pulitzer, I interviewed him about Joey Ramone dying (he was pleased at that point to talk about ANYTHING other than the Pulitzer. :)

Nutty... it actually predates official archives by quite a bit. That is, if it's what you're talking about here.