Looking for a story

I've been driving myself up the wall the past couple hours trying to find a story. I'm fairly certain it's not on here, but is on Fictionmania and possibly BC Classic. Unfortunately, I can't remember the story title, or author, and I'm not even certain on the characters' names, so the search function of FM is useless to me, and given the way the site is set up, Google can't help by using other keywords. I made a post there, not knowing that unregistered users could expect a long wait in getting posted, so I thought I'd try here as well, in hopes that someone recognizes the story.

Anyway, the story involves a homeless kid, whom I *think* is named Jack or John, or something like that, and he has some friends at a local high school. They make plans to get together, and it turns out he is TS, some of his friends pry the story out of him, and SHE was named rebecca I THINK, but given that I got no results with any of these names using FM's search (and manually going through lots of pages) I'm probably wrong. At any rate, her friends are supportive, and eventually the group of kids end up going to a river (by a bridge) to swim or something, and SOMETHINg happens, that lands them in an alternative reality.

This alternate reality has super heroes and such. It's the viral-type mutant idea (aka MORPHS, Southern Belle), rather than the genetic (Whateley, XMEN), and I believe it was called McAllister strain or some such, or possibly McSimpson. Either way I get it confused with EE Nalley's McKimpson often and easily enough. So it's something along those lines. The kids end up getting taken in by some government types, and for some reason they are exposed to this mutant strain (so they could be detained, or controlled, or simply as expendable guinea pigs; something like that), but they escape, and end up seeking help from another group. That is about all I remember.

So if anyone recognizes this, and can remember the author and/or story name, I would greatly appreciate the help in locating this one. Ta :)