I actually had a subscription to X-Men back in 1980, and this was one of the issues I got in the mail. It, along with part 2, was John Byrne's penultimate story for this run of the X-men (I think there were two mutant titles published now... hard to believe, eh?). It sure seems to have had quite the impact on the franchise now. I would never have thought anything of it, other than it was an enjoyable tale, with the hints that it was NOT the same timeline as what we were actually getting.
The big hint was in the future Colossus's middle name, which also led me to finding out the difference in male and female Russian (and other Slavic) family names. Squirrel!
So the story is Kate Pryde goes back in time, possesses her younger self and convinces the X-men to stop the Brotherhood of Evil Mutants from murdering a senator. This is a NEW Brotherhood, you'd think they'd be smarter than to use the word "Evil" in their name, but it seems to be a comic book trope to do such things.
It's full of great art and an old Wolverine getting killed- he wasn't immortal just yet, thank goodness. Holy crap, I just read the Marvel Wikia on Wolverine... that's insane. Anyway, I'm no fan of time travel stories, and while I like some Alternate Earth stories too many of them make one's head hurt.
So I'll be going to see the new X movie tonight. Seems like I'll already know much of what is going to happen. I hope the Sentinels are still purple and gray, just like the were the first time I saw them, when the Avengers defeated them in issues 102-104.