Endgame: Part One

"Endgame: Part One" is the thirteenth and finale episode of the first season of Captain Marvel, and the thirteenth episode overall. It aired on May 11, 2020.

The episode is the first part of the three-part crossover, Endgame​. The episode was seen by 28.41 million U.S. viewers.

Synopsis
Reeling from their previous loss to Thanos, the remaining Avengers, split up throughout the universe, must reunite to take on Thanos and restore the lives of everyone lost.

Starring

 * Katee Sackhoff as Carol Danvers/Captain Marvel
 * Laurence Fishburne (credit only)
 * Rob Lowe (credit only)
 * Lashana Lynch (credit only)
 * Annette Bening (credit only)
 * Ben Mendelsohn (credit only)

Special guest stars

 * Matt Bomer as Tony Stark/Iron Man
 * Justin Hartley as Steve Rogers/Captain America
 * Chris Hemsworth as Thor
 * Matthew Gray Gubler as Bruce Banner/Hulk
 * Odette Annable as Natasha Romanoff/Black Widow
 * Mike Vogel as Clint Barton/Hawkeye
 * Sterling K. Brown as James Rhodes/War Machine
 * Adam Scott as Scott Lang/Ant-Man
 * Karen Gillan as Nebula
 * Danai Gurira as Okoye
 * Mandy Moore as Pepper Potts
 * Bradley Cooper as Rocket
 * Josh Brolin as Thanos

Guest starring

 * Tessa Thompson as Valkyrie
 * Taika Waititi as Korg
 * Linda Cardellini as Laura Barton

Plot
Clint Barton, still under house arrest due to his involvement in the Clash of the Avengers two years prior and violation of the Sokovia Accords, trains his daughter Lila in archery at his homestead. She scores a bullseye and he congratulates her on her efforts. Nearby, Laura prepares a picnic while their two sons, Nathaniel and Cooper, play catch. Clint turns his attention away from his daughter for a moment to respond to his wife, but when he looks right back to Lila, she is gone. Surprised and visibly startled, he calls out to his other family members, but they too have vanished; as victims of the Snap.

Three weeks later, Tony Stark and Nebula are adrift in space aboard the Benatar. Nearly out of supplies, Stark uses the helmet from the Iron Man Armor: Mark L to chronicle their possible final days with the hope that the helmet will be recovered by Pepper Potts before falling asleep. Nebula, having developed an unlikely friendship with Stark during their journey, places him in the pilot's seat and retreats to the corridors of the ship. Tony's sleep is disturbed by the arrival of Captain Marvel, who carries the ship back to the New Avengers Facility on Earth. Stark is reunited with Potts and the surviving Avengers; Steve Rogers, Natasha Romanoff, James Rhodes, and Bruce Banner. Stark sadly tells Rogers that he lost Peter Parker upon seeing him. Rocket Raccoon sees Nebula alone and realizes that all his friends are also gone. The two sit together and hold hands in silent grief.

Now inside the facility, Rogers asks Stark if he has any clues as to where Thanos is. Tony then erupts into a furious tirade stemming from unresolved issues between them concerning Ultron and their civil war. He continues to rant that if they had stood together, they may have been able to defeat Thanos, and questions the Avengers' reputation of doing their best work only after the worst has already come to pass. After this outburst, he faints, exhausted and emaciated from his trip through space. Stark is given a sedative that will put him out for a while, giving him time to heal.

Returning to the topic of finding Thanos, Danvers proposes that they go after him right away. However, the rest of the team is not so easily convinced of the idea. Rogers tells her they don't even know where he is, but Danvers says she knows some people who might. Nebula says there is no need because she knows where Thanos is, referencing The Garden that Thanos had planned to retreat to after achieving his goal of the Snap. Based on her information, Rocket pulls up a 3-D diagram of its location and states that when Thanos used the stones on Earth, it let out a large burst of energy. The same signature appeared two days ago on a different planet.

With this new information, the team of Avengers set out to confront Thanos and retrieve the Infinity Stones in hopes of bringing half the universe's population back, leaving Stark behind. They all get aboard the Benatar and plot a course through the Universal Neural Teleportation Network to the Garden. Successfully tracking the signal to Thanos' farm in the Garden, Danvers first heads onto the planet to do recon, only to find that the planet is undefended and Thanos is alone and unguarded; with no armada, ships, or guards.

In his simple hut, Thanos goes about his daily routine; however, he is visibly crippled with horrific burns on the left side of his body from extreme use of the Stones. Danvers suddenly bursts into the hut, surprising Thanos and pinning him down with assistance from Rhodes and Banner, after which Thor severs Thanos' left arm and Gauntlet completely with Stormbreaker. To the Avengers' surprise and dismay, the gauntlet does not contain any of the Stones.

Upon interrogation, Thanos explains that the Stones would have offered "nothing but a temptation" if he kept them. After completing his goal, he deemed the Stones had served their purpose and thus he used their energies to reduce them to atoms so that what he did could never be reversed. The Avengers accuse him of lying, to which Nebula responds that while her father was many things, he was never a liar. A surprised Thanos thanks his adoptive daughter for believing him and expresses regret for torturing her but a furious Thor decapitates Thanos before he can finish, leaving Nebula to mourn her adoptive father at his side. When Rocket asks what he has done, Thor replies that this time, he "went for the head," referencing Thanos' scornful remark on his failure to kill him in the Infinity War which ultimately led to the Snap. The disheartened Avengers then depart the Garden, having realized that there is nothing they can do to bring back the disintegrated.

Five years later, Earth's remaining population has attempted to persevere against catastrophic losses. The massive genocide has traumatized the world and has stagnated much of their progress, with the path to recovery remaining slow. Rogers now participates in and/or runs a support group for citizens of New York City who are trying to cope with surviving the Snap and their losses.

In a U-STORE-It Self-Storage facility in San Francisco, a rat accidentally activates the Quantum Tunnel in Luis' Van, which had been impounded after the Snap, finally pulling Scott Lang out of the Quantum Realm. Disoriented and confused, Lang (who believes he was only gone for five hours) wanders through a post-Snap San Francisco. Deducing that something terrible must have happened, he comes across the Wall of the Vanished, a memorial site listing the names of those lost in the Snap. He frantically scans the names, hoping that he doesn't find his daughter's. Relief gives way to bewilderment as he doesn't find her name, but instead his own. Arriving at Cassie's home, he is shocked when he is greeted by his daughter, now a teenager, and the two reunite in a tearful, joyful reunion and hug. After realizing that Hope van Dyne, Hank Pym, and Janet van Dyne were among the vanished, Lang travels to the New Avengers Facility in New York with Luis' Van.

At the New Avengers Facility, Romanoff, now the leader of the Avengers, is concluding a meeting with Nebula, Okoye, Danvers, Rocket, and Rhodes, regarding the continued repercussions of the Snap throughout the universe. Following the dismissal, Rhodes remains behind to give a status update regarding his former teammate and her friend, Clint Barton, who has become a vigilante known as Ronin following the disintegration of his family. Rhodes suspects Barton is responsible for the deaths of multiple Mexican Cartel members, which upsets Romanoff. Despite his apprehension, Romanoff pleads with Rhodes to continue tracking Barton. Rogers enters the room and the two console each other, admitting that while they've now devoted their lives to helping others move on from what happened, neither of them ever can. The gloomy mood is interrupted when Lang arrives at the compound. While initially skeptical, the two realize that Lang indeed survived the Snap and welcome him into the facility. Upon arrival, he is greeted by Romanoff and Rogers, his idol, and the three begin discussing the means of his survival where Lang explains his own experience in the Quantum Realm and how they might use it to undo the events of the Snap. The trio, with limited knowledge about the Quantum Realm and time travel, seek out Stark, who is living in a simple cabin with Pepper and their young daughter Morgan, now feeling a sense of peace despite the fallout of the Snap and the weight of being unable to prevent it five years earlier.

At his lakeside home, Stark is enjoying quality time with his daughter when Rogers, Romanoff, and Lang arrive. Stark immediately understands the nature of their visit but still questions their inquiry. When Lang proposes the idea of a Time Heist, Stark quickly criticizes the idea, fearing that altering the past could erase their very existence as it stands, and expressing concern for the endangered existence of his daughter should their plan fail. Stark explains his desire to put the past behind him and tells them he's finished with the Avengers. Not wanting to give up, Rogers, Romanoff, and Lang leave and meet with Bruce Banner, the only other Avenger as smart as Tony, at a diner. After the Snap, and both Hulk's and Banner's defeat at the hands of Thanos, Banner restarted his research into Gamma Radiation and used it to morph his body to have the appearance and strength of the Hulk while retaining the intelligence and control of Banner; the development worked wonders for the Hulk's image as an Avenger as people no longer came to fear him and now idolizes him. After being told of the remaining Avengers' plans to retrieve the Stones from the past, Banner doubts that he can succeed in the time travel project, as quantum physics is outside his area of expertise, but ultimately agrees to help them try.

While Tony is washing dishes he accidentally gets a picture of his dad wet, and then comes across a picture of himself and Peter Parker. Being reminded of how he lost him in the Snap five years before, he uses F.R.I.D.A.Y. to simulate models for time travel in the Quantum Realm. Despite expecting and hoping not to fail, he succeeds just before giving up, much to his shock, by using an inverted Möbius strip model. After having done so, he discusses with Pepper the morality of time travel and about what he should do with his latest discovery: whether he should lock it up in a box and throw it into the bottom of a lake or whether he should take it to the remaining Avengers. He feels that he and Pepper were lucky that they were both spared and now have made an amazing life together, but he can't deny that everyone around them has suffered unimaginable horrors and should be helped. Pepper asks Tony if he could live with his conscience if he kept the secret to himself, and this convinces him to return to the Avengers.

At the New Avengers Facility, Banner, Rogers, and Romanoff run an experiment with time travel by trying to send Lang back in time. Instead of sending him through time, they send time through him: he turns into a child, an old man, and finally a baby before they manage to restore him to normal. Rogers leaves the room, contemplating outside of the building about what to do next. Stark arrives to extend his helping hand and asks if the whole team is getting back together. Rogers told him they're still working on gathering everyone who's available. Tony tells Rogers that he's agreeing to help on the condition that trying to reverse what Thanos did won't reset what has happened since, as he doesn't want to lose his daughter. Rogers agrees that's how it should be. The two men finally put aside their differences, and Stark returns Rogers' shield.

Nebula and Rocket arrive in the Benatar and Rhodes flies in with his suit. Scott, eating outside, sees his taco destroyed in the wind from the Benatar's landing. Banner and Rocket travel to New Asgard in Tønsberg, Norway which is now home to the few Asgardians who are left, but not before Banner offers Scott a new taco. They meet Valkyrie, who now works on the fishing docks, and she reveals Thor is not doing well. He is revealed to be depressed following his failure to the point that he has spent 5 years as an alcoholic drunk hermit who never leads the remaining Asgardians, which cost Thor a considerable amount of his power, made him overweight and spends much of his time playing Fortnite with Korg and Miek. Although Thor tries to put on a carefree attitude, he nearly breaks down upon Thanos' name being mentioned by Banner. When it seems as if an appeal to emotion will not work on Thor, Banner and Rocket convince Thor to come with them by promising him a beer.

Meanwhile, in Tokyo, Barton attacks a group of Japanese Yakuza members and dispatches them one by one, including their boss, Akihiko. Romanoff, watching the scene, approaches Barton in an attempt to bring him back to the Avengers. At first, Barton wants nothing to do with the plan, tearfully begging Romanoff to not give him any hope that his family could return. But after some convincing by Romanoff, Barton returns to the Avengers' headquarters with her.