Subtitles section Play video Print subtitles It all started in 2008, when Nick Fury told Tony Stark about the Avengers Initiative, and ten years after Iron Man hit theaters, Earth's mightiest heroes are set to face their toughest challenge: Thanos the Mad Titan. Directed by Joe and Anthony Russo, Avengers: Infinity War will feature at least 76 characters, be Marvel's longest movie to date, and revolve around six mysterious stones. Well, seven if you count Deadpool's continuity gem. Which they won't. It's a lot to keep track of. So if you need a primer to prepare for history's biggest superhero movie, here's everything you need to know before seeing Avengers: Infinity War. Who is Thanos? The Mad Titan first appeared in the mid-credits scene for The Avengers. Since then, he's popped up a few other times, but we haven't really gotten to know the guy. What does he want with Earth's mightiest heroes? "And who is the man in the purple chair? He's purple, he has a magic glove, doesn't like standing up." In the comics, Thanos is a member of the Eternals, a race of genetically-engineered superhumans who colonized Titan, Saturn's largest moon. Incredibly intelligent, uber-powerful, and born deformed thanks to a mutant gene, Thanos is absolutely obsessed with Death…the actual personification of Death. Hoping to win her love, Thanos destroys half the universe with the help of the Infinity Gems. We don't know how much of that backstory will play into the film, but it's clear Thanos means business, and when he comes to complete his rock collection, the Mad Titan might teach the Avengers what it's like to lose. Alien sidekicks When Thanos arrives, he'll have plenty of backup. The big baddie has a massive extraterrestrial army, but he's also bringing his very own evil supergroup: the Black Order. In the comics, these are Thanos' top generals, and while there are usually five, it looks like we're only getting four in the movie. The Infinity Stones We know Thanos wants to get his big purple hands on the Infinity Stones, but what are they, exactly? We know a bit about their history, thanks to The Collector. "Then the universe exploded into existence, and the remnants of these systems were forged into concentrated ingots." As a result, these six stones come equipped with devastating powers. Let's break them down. Officially debuting in Captain America: The First Avenger, the Space Stone is a blue gem inside a glowing cube, and it can open portals across the universe. And if the Space Stone lives up to its comic book potential, then Thanos might gain the ability of omnipresence, or being everywhere at once. Then there's the Mind Stone, which powered Loki's staff in The Avengers. Although it looks blue there, the Mind Stone is actually yellow and can hypnotize and manipulate its victims. The Power Stone is the purple orb that appeared in Guardians of the Galaxy. It enhances its user's strength and can waste entire planets. In the comics, it also supercharges the rest of the stones, making them all more powerful. Green and stored inside a magical locket, the Time Stone showed up in Doctor Strange and grants its user the ability to reverse time and create time loops. "Dormammu, I've come to bargain!" "You cannot do this forever." "Actually I can." The most perplexing gem is the Reality Stone. It debuted in Thor: The Dark World as a sentient red goo, and while we haven't seen its full powers yet, in the comics it can be used to alter the nature of reality itself. There's one final rock that we haven't seen yet, an orange gem known as the Soul Stone. In the comics, this allowed Thanos to control all living souls and even resurrect deceased ones. Where are they? According to the Infinity War trailers, Thanos will definitely get the Space Stone and the Power Stone. So where are the rest of the Stones? Doctor Strange placed the Time Stone inside the magical compound of Kamar-Taj, and following the events of Thor: The Dark World, the Reality Stone was given to the Collector. Though after the explosive events of Guardians of the Galaxy, who knows if he still has it. And then there's the Mind Stone, which has been everywhere. In Age of Ultron, the Mind Stone ended up in Vision's forehead, granting him the ability to fly, shoot lasers, and walk through walls. As for the Soul Stone, nobody knows where it's hiding. There are plenty of theories being kicked around — maybe Heimdall has it, maybe it won't show up until Avengers 4… or maybe Thanos has had it all along. Torn Avengers By the end of Captain America: Civil War, the Avengers were still split. Captain America has given up the shield and his star-spangled identity and gone on the run. Tony Stark, on the other hand, is still working with Vision and War Machine, and the Russo brothers promise Infinity War will grapple with the results of the last Captain America movie. If the Avengers hope to defeat the Earth's extraterrestrial threat, they'll have to put personal differences aside. Guardian grudges Star-Lord and his band of misfits will finally meet the Avengers in Infinity War, and really, this battle against Thanos is far more personal for the Guardians than it is for the rest of the heroes. Nebula and Gamora were "adopted" by Thanos as kids and turned into super assassins. Nebula has grown up hating Thanos, and getting revenge against her stepdad is Nebula's number one priority. "I will hunt my father like a dog and I will tear him apart slowly. Piece by piece." Drax the Destroyer is also on the hunt for Thanos because he had Drax's family slain. And with her own dark past involving Thanos, Gamora isn't a big fan of her adoptive father either. "When Thanos took my homeworld, he killed my parents in front of me. He tortured me, turned me into a weapon." Seeing Scarlet Chances are pretty good the Vision won't make it out of Infinity War alive, considering Thanos wants the Mind Stone, and it's lodged squarely in Vision's forehead. The Scarlet Witch also got her psychic powers from that particular gem, so maybe that's why she and Vision get along so well. There was definitely romantic tension between the two in Captain America: Civil War, and that might develop into a full-blown romance for Infinity War. Elizabeth Olsen told Nerdist that her Infinity War performance is her "most emotional arc" in an Avengers movie. It's a love affair that lines up with the comics, and it will be interesting to see how the two pull off this star-crossed affair, considering they were on different sides in Civil War. Of course, their romance will make it way more painful if the Black Order rips that rock out of Vision's head. First meeting Thor: Ragnarok saw the Hulk and Thor on a different path from the rest of the Avengers…and in a different part of the universe. And as the film came to an end, things took a very dark turn. "Meek, where are you from?" "Oh, Meek's dead. Yeah, no, I accidentally stomped on him on the bridge." Nope, not that. In Ragnarok's mid-credits sequence, the Asgardians were dwarfed by an ominous warship. MCU producer Kevin Feige confirmed that the craft is the Sanctuary II, Thanos' flagship. Chances are good that Thanos will capture the Asgardian ship — probably to steal the Space Stone that Loki most likely snatched from Odin's throne room. Home front Wakanda was once thought of as a third-world country, until it turned out to be super high-tech thanks to a particular resource. "I don't follow, what comes out of Wakanda?" "The strongest metal on Earth." But why is Wakanda going to play such a pivotal part in the film? Well, get ready for minor spoilers. According to Anthony Russo, the Mind Stone is going to end up in T'Challa's homeland, so it makes sense that Thanos and his army will battle the Avengers and Black Panther's warriors on the Wakandan plains. Black Panther has also been protecting Steve Rogers' best friend, Bucky Barnes, since Captain America: Civil War. Until recently, Bucky has been sleeping in a hibernation chamber, but in a post-credits scene in Black Panther, the newly armed super soldier was out and about again. So when the Wakandans face off against Thanos, Bucky will be right there with them. Missing Avengers Avengers: Infinity War is definitely going to be crowded, and several of the main heroes have already been lost in the marketing shuffle. Spider-Man and Doctor Strange have both shown up in the film's trailers, but where exactly are Hawkeye and Ant-Man? Clint Barton and Scott Lang are pretty big players in the MCU, but neither have appeared in the trailers or on the official poster. So have these two Avengers gone AWOL, or will they help take on the Mad Titan? According to the Russo brothers, Hawkeye is still around, but he's living a different life than his superhero buddies. As they explained: "Hawkeye's on his own journey in this movie. […] He has a unique reaction to the civil war situation that puts him in a special spot in this film." As for Ant-Man, Slashfilm reports that he'll show up in the film, and Paul Rudd is listed on the cast list. So maybe the tiniest Avenger is lurking in the trailers somewhere, but we just can't spot him. He could even be inside someone's suit. "Who's speaking?" "It's your conscience! We don't talk a lot these days." Thanks for watching! Click the Looper icon to subscribe to our YouTube channel. Plus check out all this cool stuff we know you'll love, too!