In the present day, the Avengers-- Spider-Man, Captain America, Storm, Iron Man, Giant-Girl, and Wolverine-- battle injustice in an all-ages format. And back in the 1950s, the Agents of Atlas-- Namora, Marvel Boy, Gorilla Man, Venus, M-11, and Jimmy Woo--do the same thing, but in such secrecy that the present-day Avengers have no knowledge of them.
Our story opens with the Agents of Atlas arriving at a particular spot in the Arctic, where they have been led to believe they will find something very important. And they do find what they are seeking: the frozen body of Captain America.
What's this? Captain America was thawed out by the Avengers, not the Agents of Atlas! Something fishy is going on. Someone, it seems, is monkeying with time, as the present-day Avengers have just discovered: dinosaurs are running rampant in New York! It takes a few pages for the Avengers to sort this out, but ultimately they drive the dinosaurs back through the time portal through which the beasties emerged. Brief investigation on Iron Man's part reveals that the creator of the time portal is lurking in the vicinity, and said creator just can't resist emerging and explaining his nefarious time-altering plot. A time-altering plot? No prizes for guessing that the guilty party is perennial Avengers foe Kang the Conqueror, making his first appearance in this title.
A huge chunk of exposition follows, which I can't bear to reproduce here. What it all boils down to is that Kang aims to conquer the Avengers' present, and thinks the best way to do that is to alter the past by inducing the Agents of Atlas to revive Captain America 'prematurely.' As a result of this change, Captain America eventually becomes the U.S. President, unifies the world under a single government, and then installs Kang as head of that government, as Cap is under the impression that Kang is a benevolent contemporary uniquely qualified to fill the role, rather than a conqueror from the future.
Please, no follow-up questions.
Kang's plan is being executed even as he talks with the Avengers. The dinosaur attack was a diversion, apparently, though just what the Avengers were being diverted from is not obvious. Hey presto, the timeline shifts, and now Cap is gone, Kang is a hero and leader of the world, and the remaining Avengers are under arrest for violating the local equivalent of the Registration Act. Luckily for the team, Storm is able to use her weather powers to create something analogous to Kang's time portals and travel back to the 1950s, where she, Spidey, and Wolverine hope to undo Kang's meddling.
(Giant-Girl and Iron Man can't come; their technology has changed with the rest of the world, and no longer functions properly. And the Hulk is nowhere to be found in this entire issue.)
In the 1950s, the Agents and the Avengers skirmish briefly. Mercifully, the clichéd 'hero fight' lasts only for a page before Venus uses her superpowers to calm everyone down. After a brief talk, the Agents decide to test the Avengers' claim that Kang is a bad dude by staging a fight between the two teams for Kang's benefit, one that the Agents appear to lose. (All of this happens off-panel, by the way.) Kang, discovering the Avengers have vanquished the Agents, warns them that he'll still be able to carry out his plans for conquest. Satisfied that Kang is a villain, the Agents and the Avengers unite and very quickly subdue Kang, his future weaponry notwithstanding. Then Storm (!) opens a time portal even farther into the past, to the moment when the Agents were about to revive Captain America, and the future-Agents warn the past-Agents not to do it. The past-Agents comply and abra cadabra, all is right with the timeline again! We even get a joke to go out on, as the giant ape smacks Wolverine upside the head as the time portals close.
Good times... good times.
Giant-Size Avengers #1, how do I loathe thee? Let me count the ways:
The whole thing appears to have been a hastily-executed project aimed at exploiting Jeff Parker's familiarity with the Agents of Atlas (he just wrote a miniseries about them) and the good name of Marvel Adventures: Avengers to make a quick buck.
This book sucks. The art is bad, the writing is bad, and the cost is outrageous. Jeff Parker, Leonard Kirk, and Marvel Editorial, hang your heads in shame.