Warning: This post contains MAJOR spoilers for Avengers: Endgame.
YOU HAVE BEEN WARNED.
The answer lies in the sweet puppy of an Avenger, Scott Lang (Paul Rudd), who doesn't even remember the last five years — he was trapped in the Quantum Realm, only accessible to the very, very small., like Ant-Man. This gives Scott an idea. What if the remaining Avengers use the Quantum Realm to undo Thanos' snap? The Avengers' resident "science bros" Tony Stark (Robert Downey Jr.) and Bruce Banner (Mark Ruffalo) perfect the plan.
Meet the "time heist." It's a different kind of time travel scheme than most depicted in pop culture, much to Scott's disappointment. The Avengers won't re-write the past — that's impossible. Instead, they'll creating a different future.
Essentially, they'll gather the six infinity stones and recreate Thanos' snap. In doing so, they'll bring back the people who have been gone for the past five years. They won't remember the past five years — but they'll be back.
So, let's do the math. There are six infinity stones, all of which have been held in many places over their long timelines. There are only enough Pym particles for each Avenger to travel back and forth once. That's code for, "No do-overs."
The 10 Avengers suit up into their chic, sleek quantum leap suits. Four Avengers head to New York, where three of the stones are briefly located in the same place. The others are bound for far-off planets.
Let's go over all the main stops in the characters' journeys back in time — and back to the future.
The Power Stone Mission
The Avengers: Nebula and War Machine (Don Cheadle)
The Destination: The planet Morag in the year 2014
What Happens? At first, this mission seems seamless. There are no booby traps in the ancient temple where the Orb, which contains the power stone, is held. Nebula reaches straight into the treacherous lasers and plucks out the Orb. The lasers essentially burn off her arm, but she survives. The perks of being a robot!
There are drawbacks to being a robot, too. Her future self’s presence causes her past self to run interference. Thanos figures out what future Avengers are planning. Through some clever manipulations, he switches out the two Nebulas – so there’s a traitor in the Avengers’ midst.
MCU Movie Throwback? We see a satisfying flash of Guardians of Galaxy’s opening credits — Peter Quill dancing to Redbone’s “Come And Get Your Love” before stealing the orb.
The Reality Stone (Aether) Mission
The Avengers: Thor (Chris Hemsworth) and Rocket Raccoon (Bradley Cooper)
The Destination: The planet Asgard in 2013
The Mind Stone Thor gets distracted by his mother, Frigga (Rene Russo). Off-camera, Rocket sneaks into Jane Foster's (Natalie Portman) bedroom. As you may recall, Jane discovered the aether by accident. She became its host (yep). Rocket uses an extractor tool to take it from her.
MCU Movie Throwback? Ah, back to the days when Asgard existed! During this mission, Thor encounters two of the women he lost: his mother, Frigga, and his lover, Jane. These are throwbacks to Thor: The Dark World (2013).
The Time Stone Mission
The Avengers: The Hulk (Mark Ruffalo)
The Destination: New York in the year 2012
What Happens? The Hulk has a solo mission. He travels to Doctor Strange’s (Benedict Cumberbatch) Greenwich Village apartment — only Doctor Strange doesn’t live there yet. The Time Stone is in the possession of the Ancient One (Tilda Swinton).
At first, the Ancient One refuses to hand over the Time Stone, fearing that this will create alternate branched realities which are worse than the current one. But after finding out that Doctor Strange had willingly given the stone to Thanos, the Ancient One concludes that this conversation with Bruce Banner must be part of Doctor Strange’s future foretold (the 1 in 14 million chance of the Avengers changing the outcome of Thanos’ snap). She hands over the stone, under the promise that the stones will eventually return to the exact the moment in time from which were taken.
MCU Movie Throwback? There are two. First, the Hulk, Iron Man, and Captain America land smack dab in the middle of the Battle of New York from the first Avengers movie. The Ancient One is a surprise cameo — she died in Doctor Strange, which takes place in 2014.
The Space Stone (Tesseract) Mission
The Avengers: Iron Man and Ant-Man
The Destination: New York in 2012, then New Jersey in 1970
What Happens? At the end of the first Avengers movie, Thor brought the Tesseract back to Asgard so his brother, Loki (Tom Hiddleston) couldn’t once again steal the Tesseract and unleash aliens unto New York City.
The (past) version of Tony Stark is carrying the case with the Tesseract. Ant-Man flies into (past) Tony Stark’s heart and causes him to go into cardiac arrest. He drops the briefcase with the Tesseract. Present-day Tony, dressed in a SWAT team uniform, nearly makes it out with the suitcase, but he crashes into an angry Hulk. Loki takes the fallen briefcase and uses the stone to apparate the heck off Earth.
After Cap’s mission goes similarly awry, the two heroes head to go to New Jersey in 1970, where both the Mind Stone and the Space Stone are being held. While stealing the Tesseract, Tony runs into his father, Howard (John Slattery). Howard had rescued the Tesseract when it fell into the Arctic in 1945.
MCU Movie Throwback? The Avengers movie, and anything that has to do with Howard.
The Mind Stone Mission
The Avengers: Captain America (Chris Evans)
The Destination: New York in 2012, then New Jersey in 1970
What Happens? At the end of The Avengers, the Chitauri Scepter containing the Mind Stone is given to S.H.I.E.L.D. What the Avengers didn’t know then (but know now) is that it actually was given to undercover Hydra agents. Captain America follows the Hydra agents into the elevator and pretends to be an undercover Hydra agent himself. He walks out of the elevator with the scepter; Scott takes it back to the present (but not before the past and present versions of himself have an epic Cap-on-Cap fight). Cap travels with Tony back to 1970, where Pym is working Pym Particles in his lab. He swipes some vials of particles, allowing for more quantum leaps.
MCU Movie Throwback? The three Avengers land in the Battle of New York from The Avengers. The tense elevator scene is an obvious call to a similar scene in Captain America: Winter Soldier.
The Soul Stone Mission
The Avengers: Hawkeye (Jeremy Renner) and Black Widow (Scarlett Johansson)
The Destination: The planet Vormir in 2014
What Happens? As we learned from Infinity War, the Soul Stone requires one soul in exchange for another. After a dramatic back-and-forth, Natasha sacrifices herself for the stone. Hawkeye returns alone.
MCU Movie Throwback? The scene is reminiscent of the one found in Infinity War, when Thanos pushes Gamora (Zoe Saldana) off the cliff in exchange for the Soul Stone. Red Skull, the villain from Captain America: The First Avenger, is still the keeper of the Soul Stone. Once the stone is liberated, he can go free.