One of the more curious stories in Marvel lore is the curious tale told in Avengers King-Size Special #2 of how the then current team of Avengers (Goliath, Wasp, Hawkeye, Black Panther, and the recently returned Captain America) ended up battling the original squad of Thor, Iron Man, Hulk and most weirdly Giant-Man and (of course) Wasp. It's a tale of time travel and alternate realities, one of the first and most vivid in the Marvel corpus and one of my all-time favorite comics.
The story begins in The Avengers #56 when the Aseemblers are called by Captain America to Doctor Doom's castle in upper New York State where his time machine just sits waiting for just anyone to stumble by and use it. (There are some untold tales there I bet.) They head back to World War II about the time Cap and Bucky are about to meet their destiny which results in Cap getting iced and Bucky apparently being killed. Due a peculiar moment which causes the Wasp to drowse and muck with the controls the other Avengers momentarily materialize and for a short time battle Baron Zemo and his peculiar androids who grow when stimulated. The battle is brief but it ends up with the WWII version of Cap and his partner Bucky fulfilling their destinies without realizing who else was around. Soon enough the team returns to the present day -- presumably no harm done.
They are very very wrong.
In the second part of the tale in 1968's annual we learn that their momentary appearance resulted in a change of heart when the Avengers take a different turn when the Hulk is about to leave their ranks. Instead the Scarlet Centurion appears and enlists the Avengers in his scheme to achieve peace in their time.
They do this by defeating all other super-powered heroes and villains, and as a result the present day the Cap team finds when they leave Doc Doom's digs and discover their quinjet gone is quite startling. Thor, Shellhead, Hulk and Giant-Man and Wasp are in the mansion and of course a battle rages between the two teams. The original Avengers have been warned that a group such as the Cap team will appear and assume the worst. The Scarlet Centurion appears and is not happy that the current team is not in custody.
Cap and company seek out a device called Herodotron (named after historian Herodotus) which fills them in on the alternate history they've missed out on and in fact triggered. The decide to make things right by defeating the original team and defeating the Scarlet Centurion. It's an uneven battle at best but despite long odds they succeed and then face off against the Centurion who is defeated and disappears when the team triggers Doc Doom's time machine in a certain way.
Later the Watcher appears and reveals that the Centurion is in fact yet another version of Rama-Tut/Kang the Conqueror who got lost in the byways of alternate time travel. But with that timeline now vanished and the original reinstated his existence is nullified, at least for the time being.
I consider this the Kang story that wasn't. The Centurion as designed by Don Heck is a memorable creation and he would show up many years later first in the pages of The Squadron Supreme and later still against the Avengers themselves in the final story line written by Kurt Busiek. I'd love to read this one again too, if I can make time this month for it.
Roy Thomas is at his complicated best, adding all sorts of clever little jujubees here and there for the fanboys. We see the Avengers thrash the Fab 4, Spider-Man, Daredevil, the X-Men as well as a gallery of villains of all kinds and varieties. It does suggest that if they had been able to harness the Hulk's might that the team might well have become something quite different, more about pure power than about skill and tactics.
I idea was explored more in an issue of What If? underneath a stunning Michael Golden cover.