Here, we find out that Colossus fell in love with a young healer, who then died for him, before it happened. This would be Zsaji, who isn't even introduced until issue #4 (August 1984), a couple of months after Uncanny X-Men #183 (June 1984), which deals with the aftermath of her death in as loose and non-specific a way as possible - without even naming her. And they say the publication schedules are wacky these days.
Because of this trauma - and thinking that if he fell in love with [REDACTED], then Kitty couldn't have been The One - Colossus - who we get confirmation is 19 - breaks up with Kitty, who is still 14 (although I'd expect her to be turning 15 very soon now). She mopes, as well she might, and decides to go and visit her father. She's been overdue for a visit, anyway. Colossus, Nightcrawler and Wolverine go to a bar and hit the liquor (another first). That Colossus is allowed to do that, while Kitty isn't even allowed to drive yet, sort of demonstrates the creepiness of this. But hey, this happens. And Colossus, despite his physical statute, has never been portrayed as mature. Shouldn't art imitate life? Wolverine upbraids Colossus for only thinking about his feelings, and not considering what Kitty's reaction might be. Sensible chap, that Wolverine. Could go far.
Accidentally bumping into an off-duty Juggernaut in the bar provides our quota of fighting for the issue. Colossus takes his anger out on the Juggernaut. Rather strangely, he doesn't recognise him, despite them having met in Banshee's castle in Ireland. I guess Colossus just hadn't seen the unpowered Cain Marko form, then? But why then does Wolverine recognise him?
A little cutway, with Cooper and Mystique (still undercover using the "Raven Darkhölme" identity, a forename we've seen Destiny call her by in private), shows that the government have Plans, and they involve someone called Forge. And our epilogue is Selene returning, having survived the New Mutants experience.