Warning: the following contains spoilers for Avengers: Endgame.
Avengers: Endgame explains Doctor Strange's plan from Avengers: Infinity War. The only reassurance from the enormously downbeat ending to Avengers: Infinity War of Thanos completing his mission was Doctor Strange telling Tony Stark that him giving up the Time Stone was the only way to possibly defeat the Mad Titan. It was a moment that, while also supplying the title for Avengers: Endgame, fueled enormous speculation as to what Strange meant, and what the future held for Earth's Mightiest Heroes.
With the power to see possible futures, Doctor Strange had viewed 14,000,605 futures from the moment he, Spider-Man and Iron Man ran into the Guardians of the Galaxy and were awaiting Thanos' arrival. Of all those feasible outcomes, only one had ended in their victory, the rest ending in some version or other of defeat that was impossible to come back from.
Strange was setting up a seriously long play, as evident by the five-year gap between the central plot of Avengers: Endgame and the ending of Infinity War. But it was one that ultimately worked, allowing the Avengers to reverse the snap and defeat Thanos, though it came at great sacrifice.
Doctor Strange Gave up The Time Stone In Infinity War
After both Iron Man and Doctor Strange went one-on-one with Thanos and lost, Strange makes a left-field move and gives up the Time Stone. He just hands the Infinity Gauntlet-wielding Titan the green gem, which Strange had sworn to protect as part of becoming a sorcerer, essentially guaranteeing Thanos' success.
Moments previously, Strange had confessed that out of millions of variable timelines, he had only found one single sequence of events that allowed the heroes any kind of chance for ultimate victory. Him giving away the Time Stone, an object central to Strange's entire role as a Sorcerer Supreme, was confirmation that whatever he saw was non-negotiable. It had to happen if there was to be a second round with Thanos, no matter how far-fetched or precise the path to that round two was going to be.
What's more, giving up the stone allowed everyone on that planet – Strange, Stark, Spider-Man and half the Guardians of the Galaxy – to escape being murdered in cold blood. Many of them were killed in the Snap, but could, and would, return when the Snap is reversed, whereas there's no way to revive the conventionally killed. Strange's sacrifice is a clever character beat that served a wider narrative and immediate circumstances.
Doctor Strange Knew Iron Man Had To Die For Victory In Endgame
Strange and Stark are too busy during the final act of Avengers: Endgame to deliver an exposition dump of what exactly Strange's plan was and whether it lined up with what the Avengers did, but we can presume it was probably pretty close. A lot of factors line-up to put Endgame in motion, such as Scott Lang being freed from the Quantum Realm by a rat and the presence of Captain Marvel. There's a lot of circumstances that couldn't be predicted unless you had some ability through time.
Towards the end, as the massive blow-out battle between every hero and good army in the MCU against Thanos and his Chitauri fleet rages on, several protagonists center their efforts on preventing Thanos from getting their new homemade Infinity Gauntlet. Captain Marvel, Captain America, Thor, and Iron Man all take various shots at him, all landing blows but none quite taking him out, the Purple Titan getting closer and closer to perpetrating another Snap and rending all efforts mute. Stark makes eye-contact with Strange, who raises his finger to tell him that there's one way this works out – and it's up to Tony.
Stark makes a go for Thanos' glove, but instead of trying to take the glove, he takes the stones off it. By the time Thanos realizes, it's too late, and Tony has lodged the stones into his suit to absorb their power. Defiantly proclaiming that he is Iron Man, Tony makes the Snap, and Thanos and the Chitauri are erased from existence just as half the universe's population had done previously, and a badly burned Tony dies on the battlefield after.
Strange knew it had to be Tony. He was the only one who could steal the stones and wield them himself with his suit. Every time they'd tried to remove the glove from Thanos it failed, but taking the stones off? That was unexpected. And so, the man who started the MCU was the one who saved it, just as he'd done during the invasion of the New York and Sokovia, except this time, he wasn't coming back.
Even The Ancient One Realized Doctor Strange's Idea Was Next Level
When the team travel back in time to 2012 New York to retrieve the three stones there, Bruce Banner has the unenviable task of trying to convince the Ancient One to give him the Time Stone. Though kind and receptive to his presence, the Ancient One refuses at first, not only because she swore to protect the stone, but because him taking it would splinter her timeline into a new, darker reality. Banner promises they will be returning the stones to their exact locations in their timeline after, but more importantly, tells her of Strange's decision to give Thanos the stone, and that it was all part of a masterplan.
The Ancient One yields, with the foreknowledge that Strange was to become the new Sorcerer Supreme and the keeper of the stone and that if this is all part of something he put in motion, his insight is to be trusted.
Strange's plan is massive, with a lot of moving parts. Even carried out by Earth's Mightiest Heroes, it's a long-shot to say the least, yet he had faith in them that they were capable enough to pull-through. Faith enough to hand over one of the most coveted treasures in the universe to a genocidal maniac safe in the knowledge that this defeat will only be temporary.
The Ancient One can't see past her own death, so she has a limited view of who Doctor Strange becomes. Even in what she has though, she has enough to understand his incredible abilities and precise nature. He is not a man to gamble and take risks or operate out of heightened emotions. He makes moves because they make sense, protect the Sanctum Sanctorum and serve the greater good that he has sworn an allegiance to. His plan might be completely wild, but the circumstances are calling for something that shakes the very foundations of existence, and he was always sure they'd pull through. This is universe-wide genocide they're dealing with, the time for playing safe or coy is through.
Strange saw how remarkable the Avengers are. Their unabashed heroism, cunning, and courage. They aren't easily beaten and they definitely don't take losing very well. If there's any team willing and able to take the plunge of bending time and space in order to do what needs to be done, it's them. The one chance Strange saw required a lot of them, and there's several moments where it nearly slips through their fingers, but they pull through because that's what the Avengers do. He saw that and he banked on it and, wouldn't you know it, he was right.
The Ancient One understood there was little to fear even if she wasn't going to be around to see it. After all, Stephen Strange was to be the best of them, and his Infinity War plan only proves it.
- Spider-Man: Far From Home (2019) release date: Jul 02, 2019