The Legion of Super-Heroes
The first comic series that I really got into as a kid was the Legion of Super-Heroes in Adventure Comics. Through the wonders of abpc, I have read in the last couple of days the first 22 issues in that series, from Adventure 300-321. Here are my general impressions:
There were several recurring plotlines during those issues. Perhaps the most important was the death (and later resurrection) of Lightning Lad. In Adventure #304, Saturn Girl assumed leadership of the Legion through trickery. Once in charge, she became a despot (a frequent theme; see Adventure #318), and forbade all the Legion members to use their powers for minor infractions. She was also stealing their powers secretly. It turns out that she has learned that a computer predicted the death of a Legion member using his or her power to repel an invasion, so she wants to make sure that she is the one to die. However, at the last moment, Lightning Lad disobeys her and dies instead.
This is a very significant issue in the history of DC comics. Lightning Lad was, as far as I know, the first recurring non-villain character to die in a DC story and not come back to life by the end of that story. However, they did hold out hope that he could be revived in the final panel.
"Or is it possible that the super-science of the 30th century can restore his life? See forthcoming issues of Adventure Comics for the surprising answer!"
For the next several issues, there would be a brief mention or two or Lighting Lad. In Adventure #305, where Mon-El finally leaves the Phantom Zone, the first two panels and the last one contain mentions of Lightning Lad. In Adventure #308, Lightning Lad apparently comes back to life, but it turns out to be his sister, Lightning Lass. In Adventure #310, when Ultra-Boy is (apparently) killed, Saturn Girl mentions that he is the second Legion member to die. He comes back to life at the end of the story, however as it is revealed that his death was just a trick by a descendant of Mr Myxptlk.
Finally, in Adventure #312, the Lightning Lad saga is brought to a temporary climax. The Legion resolves to dedicate itself to finding a way to revive him. Eventually a way is discovered, but it requires one of the existing members to die. Apparently Saturn Girl is the one chosen by fate, but she turns out to have been mimicked by Proty, a shape-shifting pet of Chameleon Boy's. Proty dies a hero and Lightning Lad returns to life.
There were two loose ends to this saga. First, Proty was honored with a special plaque and statue in a ceremony in Adventure #316. And Lightning Lass was redundant now, so in Adventure #317 her powers were changed to making things light, and she became Light Lass.
The other major story was the Legion of Substitute Heroes. This group was comprised of Legion rejects who still had super powers but were flawed in some way. They first appeared in Adventure #306, returned in a major role in Adventure #311 and were finally discovered by the real Legion in Adventure #315. In that issue the original Legion had a contest to see which member of the Substitutes would be allowed to join. In an upset, Stone Boy won, but declined membership preferring to stay with his old group. The highlight of the Substitute Heroes subplot came in Adventure #319 when they managed to defeat a threat that had beaten the Legion (thanks mostly to Night Girl).
There is a conscious effort to highlight the uses of the powers of the superheroes, even those with the lamest of abilities. Matter Eater Lad's super power might seem pretty pedestrian, so we see him eating his way out of a prison, and in another episode eating the inside of a meteor so that it can be used to disguise a spaceship. Bouncing Boy defeats the mighty earthquake beast in Adventure #309 by bouncing around and getting the monster to quake a mountain down on itself.
On the soap opera front, we learn in Adventure #306 that Night Girl has her eye on Cosmic Boy. And in Adventure #316 we discover that Phantom Girl is sweet on Ultra Boy. Already established long term is that Saturn Girl will marry Lightning Lad (previously shown in a Supergirl story in Action Comics). And in Adventure #317, Star Boy makes obvious his affection for Dream Girl. Not surprisingly the women admire from afar, while the men are more likely to make their interests known (although amusingly, at first all the male legion men appear interested in the platinum blonde Dream Girl).
In an interesting twist, the ground is laid for the Legion's major villain, the Time Trapper in Adventure #317. The story (and the one in Adventure #318) mentions the Time Trapper as if we have already met him, but he does not actually appear until Adventure #321.
One thing that I had not noticed reading the stories as a youngster was the special problem posed to Legion writers by the characters of Superboy, Mon-El and Ultra Boy (and to a lesser extent Supergirl). Their tremendous powers make it difficult to maintain the illusion of danger to the other Legion members. As such, the writers frequently had them responding to some other emergency. In both Adventure #317 and #318 they are shown attempting to break through the Time Trapper's barrier. It's very likely that the villainous Trapper was developed to give them a continuing reason to be away from the Legion.