Stops us if you've heard this before. So there is an invasion force that arrives from another universe, gleaming in golden armor, seeking to plunder Earth of its resources and gain dominance over those whom they view as inferior. This scenario actually played out twice, on Earths One and Two. Here's how it played out.
The Dronndarians enlisted the aid of Two-Face to purchased pure energy from them, which was a scam in order to siphon deadly energies from their native universe into Earth-One's realm in order to save their world and all they knew. Inhabiting the statutes of Napoleon, Julius Caesar and Benjamin Franklin, the trio from Dronndaria thought a greedy criminal like Two-Face would jump at the chance of such power. However, the felon realized the threat this posed to his world and sought the help of the Justice League of America. Side-by-side, this unlikely alliance was able to overturn the nefarious scheme, thereby returning to their native universe only to transform into beings of pure energy as they were actually supposed to become.
On another dimensional plane decades prior, Earth-Two was being invaded by gold plated men disguised as circus performers that were in fact raiding that world of its precious iron. Investigating a series of weird crimes by alleged metallic men following a tip by a reporter of the Boston Globe named Benson, the Justice Society of America were stunned to learn that the told plating was the natural skin of the thieves. Confronting their leader Aurikon and his minions, the Society were soon overpowered. Seeing the means of the Golden Men's escape, the Society decided to follow them.
When they awoke, they found themselves on what seemed to be a caterpillar shaped ride that turned out to be a dimensional transport device, which brought them to the Golden Universe that their adversaries originated from, known as Xenca.
As to the Justice League, after their victory versus the Dronndarians it turns out that their former foes' secret allies were the Weaponers of Qward from the Anti-Matter Universe, old adversaries of the Green Lantern and his Guardian seers. Exploiting the situation while enlisting the help of Two-Face, who felt betrayed when the League repaid his help by returning him to Arkham Asylum. They may regret that decision.
Sneaking up on Lantern and then recruiting Two-Face, which this time he accepts out of vengeance towards the League, the Thunderers of Qward and their masters stealthily utilize their new ally to implant devices on each Leaguer that confronts a Qwarding, thus making them pawns in a deadly game. The goal, to destroy the positive matter universe that the Anti-Matter Weaponers view as their chief rival, is still thwarted when the League get wise to this ploy and defeat the golden goons. And for all his troubles, Two-Face was returned to the Asylum.
And to finish up the tale of the Society in the Golden Universe, we pick up when the Society are revived by that world's queen Myrla and her men, after which they quickly inform her of her half-brother Aurikon's thefts. Turns out that the iron from Earth-Two is needed in order to power large robots that have lied dormant during 1000 years of peaceful relations on Xenca. Craving power, Aurikon and his forces felt this was the means by which they could seize control of their world, perhaps even their entire universe. Splitting off into teams, the Society like their League counterparts are quickly able to deduce their enemies' plans and quickly overturn them. After defeated Aurikon and his forces, the team returns to their native universe.
While Qward had a dimensional access point to Earth-One, apparently Xenca had something similar with Earth-Two. And just as Qward's Anti-Matter Universe was in direct opposition, due to the laws of physics, to that of the positive matter universes... so to was the Golden Universe in direct opposition to the nature of the carbon-based universes. However. while Qward would continue to grow into being a cesspool of despotism, Xenca would maintain its known attribute as a beacon of civil society.