There's only thing that burns me about it; when I was a kid, I saw this book EVERYWHERE. Every department store had it, many times paired up with some other book in a plastic bag. The Fantastic Four weren't really my thing so I overlooked it a number of times. To have known that it would include a brief appearance by a personal favourite character that I would want 30 years later, I would have jumped all over it. Ah well.
So what's the story here? A mysterious worldwide power failure leads the Fantastic Four to investigate the possibility of a "polar disruption". The FF fly north, through Canadian airspace, causing Guardian (Vindicator at this point) to do some investigating of his own, good little soldier that he was.
It would have been cool to have Guardian tag along on this mission but this is the extent of his appearance in the book, unfortunately.