Warning! Spoilers ahead for Justice League Unlimited #5!The worldwide terrorist group Inferno and their true identities pose a huge threat to the greatest heroes of the DC Universe.

In Justice League Unlimited #5 by Mark Waid and Dan Mora, the team keeps an eye on the G20 summit, fearing Inferno will attempt to disrupt the meeting to cause global chaos. Unfortunately, the villains are steps ahead of the League and one of Inferno's infiltrates the summit to disappear the leaders to an extradimensional plane.

Thankfully, the League finds the plant, revealing them to be Gorilla Grodd, who has also gained Martian Manhunter's powers. After the team rescues the rest of the G20 leaders, Grodd escapes and s up with his fellow Inferno masterminds, the Legion of Doom.

Justice League's New Threats Are Actually Their Oldest Foes

The Legion of Doom Returns to Permanently Defeat the Justice League

The Justice League re-formed bigger and better than ever after the events of Absolute Power. But their latest era immediately came under siege by a group calling themselves Inferno. The mysterious terrorist group has made planned attacks on the world from destroying mining towns to setting the entire Amazon Rainforest ablaze. Unfortunately, while Inferno claimed to know the Justice League, even referring to them as 'old enemies', the team had no clue who was behind the organization, much less what the group was even trying to accomplish with all of these attacks on the Earth's most vital parts.

But why is the Legion of Doom even together? Mister Terrific points out early in the issue that the team isn't active and that like Lex Luthor or Sinestro are even working with heroes. But if one takes a close look at the Legion, here, they can see that villains like Sinestro or Scarecrow are wearing older versions of their costumes. This actually makes a lot of sense when one also re that Justice League Unlimited is about to crossover with Batman/Superman: World's Finest for the "We Are Yesterday" event, which will span multiple eras of the DCU.

The Truth Behind the Legion of Doom and Inferno May Be in the Past

The League Has a Serious Threat in Their Oldest Villains

While the details of "We Are Yesterday" are few, a crossover between the two comics, which are set in different periods in DC history, should clear up a few things about why the old-school villains formed Inferno. But whatever's brought them back, the League is in serious danger. Inferno's acts so far have proven that the Legion has upgraded their methods and ambitions and that they're not the silly villains of yesteryear. Whatever the Legion of Doom has planned, the Justice League had better be prepared because their old foes aren't playing around.

Justice League Unlimited #5 is available now from DC Comics.