There's an interesting story to that issue. I read an interview with Paul Levitz about issues 250-251.
Apparently, Jim Starlin had drawn and wrote a 60-something ending to a storyline that had abruptly ended in issue #239. It was supposed to be for a giant-sized issue of Superboy and the Legion. For whatever reason, the story was shelved. Later, Levitz was asked to rewrite the story for issue #250. According to Levitz, he took Starlin's art pages and did a "52 card pick-up" and changed things all around in order to fit the new storyline he had written. It turned into a two-issue story with some art added by another artist. According to Levitz, Starlin was understandably very upset with it all.
Several of Starlin's art pages were discarded and Starlin later sold those pages at conventions, so the odds of ever seeing the original storyline he had envisioned are very slim to none.