Avengers: Infinity War brings two big Marvel Universe concepts to the center of its plot: The fabled Infinity Stones, and the villainous warlord Thanos, pulling from decades of Marvel Comics canon.

But don’t worry if you’re not sure where to start. You’re not alone! It can be hard to know exactly what to read beforehand. And we’re here to help. Here are two major story arcs that look like the most likely sources for Infinity War’s inspiration, ready and waiting for new readers to pick them up.

The Infinity Gauntlet

Here’s the story that started it all: The Infinity Gauntlet. It’s not the first time Thanos tried to obtain all the Infinity Gems (known in the Marvel Cinematic Universe as the Infinity Stones) — he already tried to do it once without realizing their true power, and was stopped by the Avengers. And it wasn’t the first time Thanos attempted to gain the ability to bend all of reality to his will — he’d already tried to obtain the Cosmic Cube in an arc of Captain Marvel.

But 1991’s The Infinity Gauntlet — written by Thanos’ creator, Jim Starlin, and drawn by George Pérez and Ron Lim — is the story that forever linked Thanos and the Infinity Gems. As a big, popular crossover event with cosmic stakes, it’s been called Marvel’s Crisis on Infinite Earths, and it left a commensurate mark on Marvel canon.

Instead of focusing on the search for the Infinity Gems, Infinity Gauntlet opens with a bang. Thanos has already obtained all six Gems on its first page — he is fully omnipotent, and one of the first things he does is kill half of the universe’s population with a snap of his fingers. How our heroes managed to triumph over Thanos in spite of his power has become one of the Marvel Universe’s biggest comic book blockbusters.

You can read the whole thing on Marvel Unlimited, or pick it up on Comixology or in hard copy.

Infinity

But while Avengers: Infinity War is definitely pulling from the “Thanos tries to get all those gems on a glove” aspect of The Infinity Gauntlet, there’s another, more recent Avengers story from which the film has borrowed elements. Ironically, it’s a Marvel Comics story that’s younger than the Marvel Cinematic Universe itself, even a year younger than Avengers.

Written by Jonathan Hickman and drawn by a slew of artists, Infinity is a 2013 six-issue miniseries/crossover in which Thanos attacks Earth in an effort to locate his long-lost half-Inhuman son — so he can kill him. He brings some people with him who will be familiar to anyone who’s been paying attention to the Infinity War trailers: a powerful alien strike team known as the Black Order and some four-armed aliens called the Outriders. In Infinity War, the Outriders appear to be a formidable alien army, and the Black Order has taken on the name “The Children of Thanos.”

There could be more more elements of Infinity War that were borrowed from Infinity — like Proxima Midnight forcing the Hulk back into his Bruce Banner form just by hitting him with her spear, maybe — but we won’t know until we get our eyeballs on Avengers: Infinity War itself when it hits theaters on April 27. In the meantime, you can grab Infinity on Marvel Unlimited, Comixology or in a collected edition.

Happy reading!