...as quickly presented here.
A look at a couple of team-ups of Flashes Barry Allen (from Earth-1) and Jay Garrick (from Earth-2), featuring Golden Age villains like Vandal Savage and Rag Doll (plus one or so.....).
Death Of An ImmortalSolomon Grundy, in Flash #215 (May, 1972) by Len Wein, Irv Novick, Frank McLaughlin and Dick Giordano, under an emotional cover by Neal Adams and Dick Giordano.
The team up does being with a little confusion...
Nothing illicit going on, just a little multiple Earth confusion. Jay was suppose to get an award as the Flash from Keystone City, but he's missing....so, Barry jumps in Jay's costume to take his place, hoping to spot someone that will be surprised that he is there. That doesn't pan out, and on his way to his next idea, Barry saves an old man from an out of control truck...who surprises Barry by letting him know that he isn't the Flash (of Earth-2).
But, what about the old man? He wasn't what he appeared to be....he was Vandal Savage! The immortal villain found out that he wasn't as immortal as he thought, and needed to be exposed to the meteor again to keep his life going, and sent Jay into Limbo to retrieve it, yet found the powers of one speedster wouldn't be enough, so came up with this plan to get it, using items he got from his fellow Injustice Society of the World members.
They defeat Tempus, and work their way through other time hurdles to leave Limbo after passing through the End of Time, and back to where they entered (finding out of Vandal Savage's role as they go). The meteor shows up and Vandal is there for it to strike him....and both disappear!
Jay returns next in the 11th JLA/JSA team-up, that introduces the Freedom Fighters, with his wife Joan having last appeared in a Jay Garrick solo tale in Flash #201 (November, 1970) and appearing next in the next Flash team-up...and villain Vandal Savage was last in the Flash team-up that revived the JSA, and appears next in an upcoming Flash team-up to be covered later.
The Rag Doll Runs Wild
Barry Allen decides to have lunch with an old friend's wife...
...but, to do that, has to travel to Earth-2 to meet Jay's wife, Joan Garrick.
Along the way, he stops a break in at the Central City Community Center (the place where Barry first went to Earth-2), quickly dispatching the Walton Gang, and heads off to the alternate Earth.
Thinker, without his snazzy purple costume he got fighting the two Atoms, returns with the Injustice Society of the World to face the JSA with Power Girl in their return in All-Star Comics in the mid-1970s. The issue also has reprints, including some of the Golden Age Flash and Johnny Quick!
Something to think on over time....and more alternate Earth teams to follow in the future!