Since its 2008 inception with the first Iron Man film, the Marvel Cinematic Universe (MCU) consistently proves itself as a box-office juggernaut, grossing over $10 billion by early May of 2017.

Various factors help to flourish the franchise, like the backing of the second largest media company on Earth and clever marketing techniques. However, one aspect exists that arguably plays a larger role in the success of the MCU than all others—the characters.

Serving as the backbone of this universe, Marvel has presented viewers with an entire universe filled to the brim with colorful and complex characters, heroes and villains alike, and the upcoming Avengers: Infinity War will bring together the vast majority of said characters to band together and fight the Mad Titan Thanos.

With a reported 67 characters in the film, it may seem easy to lose oneself among this super-powered menagerie. For those planning to see the film, the following list provides a brief recap of the exploits of the essential cast in their last appearance, as well as what to expect from them in the third Avengers film.

Captain America

Perhaps best known as the first superhero on Earth, Steve Rogers, also known as Captain America, gained his powers due to a military experiment designed to engineer a super army to combat Nazi Germany. After a sabotage left the Captain as the sole test subject, the US army utilized Rogers as a super soldier, until a botched mission left him frozen in ice for decades. When last seen in Captain America: Civil War, Rogers came into conflict with his friend and longtime teammate Iron Man over the Sokovia Accords, the fictional government legislation to regulate superheroes. After saving best friend Bucky Barnes, known as the Winter Soldier, from the Armored Avenger, Rogers abandoned the mantle of Captain America and became a fugitive of the law. According to director Joe Russo, his road forward involves figuring out his place in the world “without the shield.”

Iron Man

Born to Howard and Maria Stark, billionaire Tony Stark, after realizing that weapons of his own making put innocents in danger, decided to become a superhero to prevent the loss of life, eventually serving as the primary benefactor of the Avengers upon his joining. After his battle with Captain America, Iron Man returned to the New Avengers Facility, now effectively the new leader of the remaining Avengers. Spider-Man: Homecoming depicted the hero serving as a mentor for the titular wall-crawler, most notably creating the upgraded pieces of equipment he utilized. When asked about his status, co-director Joe Russo stated during a Facebook Live Q&A that Iron Man “senses this…threat approaching, so he is doing everything…to keep the Earth safe.”

Thor

The Asgardian God of Thunder and son of the late Odin, Thor initially courted war in his youth, until his father realized his son lost sight of what the name of his family meant. After banishing him to Midgard, Thor learned humility and compassion, and after redeeming himself, foiled a scheme by stepbrother Loki to wipe out the Frost Giants, and later stopped another scheme alongside the Avengers. In Thor: Ragnarok, the God of Thunder came into conflict with the sins from the past, facing both the fire demon Surtur and exiled sister Hela, the former of whom destroyed the Asgardian homeworld. Despite receiving the crown as King of Asgard, the exodus of his people led them to Sanctuary II, the main starship of Thanos. In an interview with ComicBook, Joe Russo promised fans that Thor will “have a real emotional motivation” to defeat the Mad Titan.

Hawkeye

A former special agent for S.HI.I.E.L.D., Clint Barton served directly under Director Nick Fury for tears, until his mind control at the hands of Loki. After breaking free, he joined the Avengers as a founding member, aiding in the defeat of Loki, and later the defeat of Ultron. After his imprisonment and subsequent escape from the Raft, he became a fugitive of the law, while returning to his family. Unlike most other heroes, the master Marksman of the Avengers seems nowhere in sight among promotional material, to the point of Internet memes popping up on the radars of the creators. Despite this, director Anthony Russo confirmed that that events of Civil War “puts him in a special spot this film.”

Scarlet Witch

A former Hydra agent and ally of the villain Ultron, Wanda Maximoff, after losing her family in a missile strike, grew up with no one but her late brother Pietro, also known as Quicksilver. During a protest against foreign intervention, Maximoff faced an offer to save her home of Sokovia from invading forces, using her powers for evil before joining the Avengers. Last seen escaping the custody of General Thunderbolt Ross, a tie-in comic revealed that Wanda Maximoff fled to Scotland to start a new life with teammate and potential love interest Vision. Paul Bettany, the actor who plays Vision, revealed in an interview while filming scenes for the film on the Atlanta set that the romance between the two heroes will play an essential role, claiming that “Vision’s…on this quest to understand what being human is and…Scarlet Witch [has], in a large degree, helped him figure that out and what love is.”

War Machine

Best friend of Iron Man, War Machine acquired his armor after an altercation with a drunken Tony Stark. After his recovery, Stark allowed the hero to utilize upgraded armors to aid the US Air Force before joining the Avengers after helping them defeat Ultron. After his accidental crippling at the hand of Vision, James “Rhodey” Rhodes retired from his military and superhero careers, receiving a harness from best friend Tony Stark to aid in his movement; however, the looming threat of Thanos seems to require his services. Actor Don Cheadle stated his relationship with Iron Man “has deepened since the last event.” The same interview with entertainment website DigitalSpy also revealed Rhodey will feel “a little ambivalent” toward the idea of returning to the Avengers.

Spider-Man

After a bite from a radioactive spider granted Queens high schooler Peter Parker superpowers, the young hero used said powers to stop street crimes in New York, eventually leading to his early recruitment into the Avengers. Among the newest heroes introduced in the movies, the Web-Slinger ended his first solo outing rejecting an invitation to the Avengers, electing to keep fighting for the “little guy.” Marvel Studios President Kevin Feige stated Spider Man will play a larger role “because of Homecoming and…what people know from it, but it’s about on par with (Civil War).”

Black Panther

After the death of his father in a bombing, Prince T’Challa of Wakanda seeked vengeance of the Winter Soldier, who he wrongly believed killed his father. After discovering the identity of his true killer, the newly crowned king decided to offer the Winter Soldier asylum in his home while also clearing his mind of Soviet programming. In the aftermath of the box office success of his solo film, King T’Challa seems on top of the world. At the end of Black Panther, the king attended a United Nations conference, in which he pledged to share the resources of Wakanda with the rest of the world. While his role may remain largely unknown, his home of Wakanda will play a major role in the upcoming flick, serving as the “the setting for the entire third act of the film,” reportedly because Captain America wants to keep Vision in a secure location.

Loki

Last seen conversing with adopted brother Thor over the merits of his return to Earth, God of Mischief Loki seems on a collision course with former ally Thanos, one which may cost him his life. Media website Inquisitr theorized his loss of the Mind Stone, one of the six Infinity Stones Thanos desires, in the first Avengers film and may hint towards ill will between the two; an alternative theory suggests that his holding of the Tesseract, a vessel for an Infinity Stone, may signal a betrayal of Thor, paying off an “old debt,”as Polygon states.

White Wolf

Best friend of Captain America, ex-Hydra assassin Bucky Barnes recently underwent cryo-treatment in Wakanda, so as to remove his Soviet programming of old. Entertainment Weekly revealed the soldier will no longer use his old alias, now referring to himself as the “White Wolf.” Along with that new code name comes a new vibranium arm created by Shuri to replace the one destroyed by Iron Man.

Star-Lord

Abducted from Earth as a boy, Peter Quill, aka Star-Lord, joined the intergalactic Ravager gang as a young child before striking out on his own. After discovering an Infinity Stone, Quill allied himself with four other criminals to protect the gen from the Kree fanatic Ronan, and continued to serve as the leader of this team. Despite the deaths of biological and surrogate fathers Ego and Yondu Udonta, respectively, Peter Quill, aka Star-Lord, continues to lead the rag-tag team of cosmic misfits in their adventures across the universe. While the size of his role remains up in the air, it seems a somewhat adversarial relationship between Quill and the God of Thunder will blossom, as a recent TV spot depicted Quill mocking Thor.

Gamora

Adopted daughter-turned enemy of Thanos, Gamora seems prepped to play a major role in the film, as her personal knowledge on the Mad Titan could prove valuable in aiding the heroes. Even co-director Joe Russo confirmed as much, saying “a lot of the film is told from the point of view of Gamora, and I think she has a really fascinating arc in the movie.’’

Drax

After losing his wife and daughter to a Thanos employed Ronan, Drax the Destroyer went on a galactic killing spree, attacking any and all with any association to the Kree, which eventually led him to meet his future teammates. Arguably the character in the film with the largest grudge against Thanos, Drax seems unlikely to help defeat Thanos. However, a relatively new fan theory claims he could turn the tide against Thanos and his forces. In his first battle with warrior Ronan, the Kree warrior threw the Destroyer into a vat of yellow liquid. While Groot prevents him from drowning, his coughing up of the liquid indicates a portion possibly ended up processed by his bodily functions. The theory emerges when one remembers that when the Guardians arrived on Knowhere, the head of a dead Celestial, she mentioned spinal fluid among the resources mined. Given how the MCU plans story elements in advance, perhaps Drax will receive a power boost.

Groot

Longtime partner and best friend of Rocket Raccoon, Groot aided Rocket in his schemes before his arrest at the hands of Nova. While in the Kyln super prison, Groot encountered his future teammates, playing a crucial role in defeating Kree Public Accuser Ronan. Fitting of his rebirth into an infant form, it seems Groot will gain a parent figure in Infinity War. Actor Terry Notary, who plays Groot, stated in an interview that Groot will “find a mentor to look up to and to model himself after.” Thor seems like the most likely to fill this role, as most of the trailer shows the two together, and toys hint that Groot might lend wood to the God of Thunder to build his new weapon.

Hulk

The resident powerhouse of the Avengers, the Hulk, despite his immense power, seems more useful to the Avengers as an adviser rather than a member. According to Mark Ruffalo, “he’s also privy to some information” essential for the survival of the Avengers, possibly implying an early encounter with Thanos, supported by a recently released clip of the film. The Hulk will also continue developing in a character arc “starting with Thor 3 and…into Avengers 3 and 4.”

Black Widow

A former Soviet spy, Natasha Romanoff, better known as the Black Widow, later joined S.H.I.E.L.D after Hawkeye chose to recruit her to the organization rather than kill her like assigned; her combat and espionage prowess later led to her recruitment into the Avengers. Last seen as a fugitive of the law after aiding the escape of the Winter Soldier, a prelude comic to Infinity War revealed that Romanoff joined up with Captain America and Falcon, covertly taking out terror cells. Actress Scarlett Johansson revealed in an Entertainment Weekly coverage event that Widow, in the aftermath of Civil War, “hardened even more than she probably was before,” likely as a result of her falling out with Iron Man.

Thanos

First introduced as the puppet master behind the Chitauri invasion of Earth, Thanos also pulled the strings of Ronan before his defection; the failures of both villains motivated the villain to conduct his own search for the Infinity Stones. The primary villain of the MCU, fan’s expectations for the Mad Titan to show out seem higher now more than ever, and from what Marvel has revealed so far, fans seem in for a treat. Motivated to wipe out half the universe due to an extinction-level tragedy befalling his species, actor Josh Brolin likened the villain to Quasimodo of The Hunchback of Notre Dame, stating: “He stuck out. He was an anomaly. He was a freak, and that lent to this apparent insanity.”

With an ensemble cast such as the one in Infinity War, a refresher on all the characters can serve to enhance the movie experience, as viewers can avoid confusion seeing multiple heroes on screen. Avengers: Infinity War opens in theaters on Friday, April 27.