Just a bit of info on Helena's universe for the non-comic readers (or those only really familiar with the more modern DCU)Earth-Two
- Super-heroes first appeared on Earth-Two in 1938/39, with Superman (who was never Superboy) and Batman being among the very first. Many more followed, including Hawkman (Carter Hall), the Flash (Jay Garrick), Green Lantern (Alan Scott), and many more.
- Most of these heroes (with the initial roster being Superman, Batman, Hawkman, Doctor Fate, the Spectre, Green Lantern, the Flash, the Atom, Hourman, and the Sandman) banded together to form the Justice Society of America, after preventing an attempt on the life of FDR by valkryie warriors summoned by Hitler using the Spear of Destiny. The influence of this magical item is also what kept the likes of Superman or the Spectre from simply flying off to Germany to end World War II early.
- Other heroic teams of that era include the Seven Soliders of Victory (Crimson Avenger, the Vigilante, the Star-Spangled Kid, Stripesy, the Shining Knight, Green Arrow, and Speedy) and the All-Star Squadron, which was a group which actually incorporated all mystery men of the day, but was built around a core of Liberty Belle, Johnny Quick, Robotman, Commander Steel, Firebrand, and later the Tarantula and Amazing Man.
- The JSA eventually was forced into retirement by the House Un-American Activities Committee, refusing to unmask under the suspicion of Communist ties. They remained in retirement for a little more than ten years. During this time period, Clark Kent marries Lois Lane, while Bruce Wayne marries Selena Kyle.
- Eventually, Barry Allen, the Flash of another Earth, accidentally penetrates the vibratory barrier separating his Earth and that of the JSA. He teams with Jay Garrick several times, before the JSA makes a comeback to team up with the Justice League of America. The JSA's world, having been discovered by someone from the JLA's world, is named Earth-Two, while the League's Earth becomes Earth-1.
- In the late seventies, the JSA welcomes some new blood, including the Star-Spangled Kid (pulled from a timewarp), Power Girl (Superman's cousin and Earth-Two counterpart to Supergirl), and the Huntress.
A number of Earth-Two heroes are retired or semi-retired, returning to action when only when the situation requries it.
A great number of the heroes of Earth-Two, including Superman, Wonder Woman, and the late Batman, are married.
A number of the heroes, including Wonder Woman, have children.
Earth-Two has a few noticable differences besides the presence of an older generation of super-heroes. Most notable, South Africa abandoned apartheid sometime in the seventies, and Quebec is an independent nation.
Dick Grayson never abandoned his Robin identity (though he did update his costume)
Most of the heroes are now in their mid to late fifties, but due to their extraordinary abilities and exposure to various forms of magic over the years, have considerable vitality still.
In pure narrative terms, there's a much greater bond of trust between heroes. Everyone knows everyone elese's origin and secret identity.
And of course, the heroes, in fact the whole Earth, is just a bit more squeaky clean. Most notable, of course, when applied to Batman. This is the Batman of the fifties, with all manner of adventures against aliens and wacky costumes, the Batman who drove the Batmobile through downtown Gotham in broad daylight, smiling
Gotham itself, is and always was, also home to Green Lantern as a local hero, and the JSA has its headquarters there.
Of Gotham and Batman, to quote from the Earth-Two Superman...
"Our Gotham wasn't covered in grime and dirt. Things were rough, but during the days, the sun still managed to shine. As the commishoner, the Bruce Wayne I knew learned to live past the death of his paretns. He opened his heart and married."