Phase Three, the third and final output of Marvel Studios’ cinematic franchise kicks off this year with Captain America: Civil War in April, a de facto Avengers 2.5. Civil War begins the long march to 2018’s and 2019’s Avengers: Infinity War, the climactic two-parter that will end the Marvel movie era as we know it before refreshing with 2019’s Inhumans. But exactly what the heck makes a war “infinity”?

Avengers: Infinity War will be taking its cues from the Infinity mini-series trilogy, beginning with the major crossover mini-series The Infinity Gauntlet published in 1991. Written by Jim Starlin, the story begins when Thanos, a cosmic supervillain inspired by DC’s Darkseid and Starlin’s freshman year psychology courses, collects the Infinity Gems — six powerful stones that when combined become a weapon capable of unspeakable power. Thanos creates the Infinity Gauntlet, which allows him to harness the gems’ powers.

Thanos is eager to win the affections of Mistress Death by doing her bidding: Erasing half of sentient life in the universe. With the snap of his fingers, Thanos does exactly that, and in his massacre a ton of the X-Men, the Fantastic Four, and Daredevil are killed. Of course, the remaining heroes of the Marvel universe band together to stop Thanos.

And they succeed. Kinda. As Thanos becomes so powerful he becomes the living embodiment of the universe, leaving the Gauntlet and the Infinity Gems unattended. Nebula, Thanos’ granddaughter, takes the Gauntlet and reverses Thanos’ destruction and reign of terror. Adam Warlock, a cosmic being with a tumultuous relationship with Thanos, takes the Gauntlet under his protection despite objections that he keeps the Gauntlet intact. While Thanos isn’t killed, he is left powerless working on a farm and the heroes decide he is no longer a threat.

That’s The Infinity Gauntlet in a nutshell, and probably what Infinity War will most be adapting. In the 1992 sequel Infinity War, Adam Warlock splits his “good” and “evil” psyches to become a logical being worthy of harnessing the Infinity Gauntlet. Naturally it backfires, and his “evil” persona Magus creates a replicate universe of evil doppelgängers of the Marvel superheroes. You can guess what follows in a series titled Infinity War.

A year later, Marvel finishes the trilogy with Infinity Crusade, which pits the Marvel heroes against the “good” side of Adam Warlock’s dualities, the Goddess. While she’s “good” in theory, in practice she is the same kind of extremism Magus represented and was still a threat to all of reality.

In the movies, Marvel has been building towards the assembly of the Infinity Gems (actually “Stones” in the MCU). The first of which, the Tesseract (the Space Stone) appeared 2011’s Captain America: The First Avenger, while Thanos himself was introduced a year later in 2012’s The Avengers mid-credits.

The other Infinity Gems have made their MCU debut: the Aether (Reality Stone) in Thor: The Dark World, the Orb (Power Stone) in Guardians of the Galaxy, and the Mind Stone in the Chitauri Scepter (now Vision’s forehead) in Avengers: Age of Ultron. The Gauntlet, meanwhile, was seen in the end credits of Avengers: Age of Ultron.

Will Avengers: Infinity War go as far as Infinity Crusade? Doubtful. The MCU has spent the last eight years since 2008’s Iron Man building towards Thanos — played by Josh Brolin, who rocked an Infinity Gauntlet at Comic-Con 2014 — without any mention of Adam Warlock whatsoever.

Josh Brolin plays Thanos in the Marvel Cinematic Universe.

Rumors indicate he may be introduced in Guardians of the Galaxy 2, but Thanos is enough of a threat. Adding more bad guys turns Infinity War into an Infinite Clusterfuck.

This weekend at Wizard World New Orleans, the duo directors of Infinity War Joe and Anthony Russo spoke to various outlets about the MCU’s climax and dropped a staggering number of characters that will be featured: 67.

“We have so many characters we’re dealing with,” Joe Russo told ComicBookMovie. “We’re breaking ground on Avengers: Infinity War. We have a board with 67 characters on it.”

In a separate interview with ComicBook, the Russos disclosed Infinity War will be a uniting of all the separate Marvel stories into one, meaning we could see the likes of Daredevil rub elbows with Iron Man.

“People will not be disappointed in the amount of characters in the movie,” Joe Russo told ComicBook. “The concept of Infinity War is that the Marvel universe unites to battle the greatest threat to the world and universe that you’ve ever seen, and we’re going to honor that concept.”

Photos via Getty, Marvel