This article contains spoilers.
Time is without a doubt one of the most complex storytelling devices known to mere mortal writers. When fantasy and sci-fi writers dabble with time manipulation and time travel in their stories, readers and viewers tend to be lost in a sea of doubts and questions.
The Time Stone is one of the six Infinity Stones that Thanos pursues in Avengers: Infinity War, and it is the penultimate gem he collects in the final act of the film, after Doctor Strange surrenders it in exchange for keeping Iron Man alive.
Thanos teleports directly to Earth after acquiring the Time Stone, and in a dramatic plot twist, reverses a few minutes on the clock to undo Scarlet Witch’s destruction of the Mind Stone. He intervenes and plucks the Mind Stone out of Vision’s head, killing the android and completing the Infinity Gauntlet, which results in that lethal finger snap.
Since the movie, fans (and even myself) have wondered why Doctor Strange couldn’t have just done the exact same thing throughout the movie.
By the time the sorcerer of the mystic arts is made aware of Thanos’s conquest, only two Stones had been collected. He was still in possession of the Eye of Agamotto, the container of the Time Stone, so he could have easily turned back time to undo the events of the Stones Thanos acquired subsequently: the Reality Stone and Soul Stone.
I’ve given this seeming story loophole enough thought, and here’s why I think Doctor Strange ultimately didn’t (or couldn’t):
He wasn’t aware when the Reality and Soul Stones got taken
Thanos acquired the Reality Stone at Knowhere, then the Soul Stone at Vormir. These basically happened planets away from Doctor Strange, who was following Iron Man and Spider-Man to Titan. He couldn’t have reversed time to undo them.
We don’t know if Doctor Strange can reverse hours of time
When Doctor Strange eventually realized during the battle on Titan that Thanos’s collection had expanded from two to four, it had been at least hours.
He technically could have reversed time at that point, but that said, we don’t know how well-versed Doctor Strange is in wielding the Time Stone. The sorcerer previously reversed minutes (a hour tops) of time in his eponymous movie, but there’s no confirmation the former surgeon actually learned how to turn back hours or days.
Besides, as explained by Mordo in the 2016 movie, manipulating time spawns alternate timelines and parallel universes, a complicated repercussion that would only be exacerbated by extended time travelling. Perhaps Doctor Strange wanted to avoid this.
Regardless, he was unwilling to wield it in the presence of Thanos
But even if Doctor Strange had mastered the Time Stone and could go back hours, days or even weeks in time, the sorcerer was fiercely protecting the Eye of Agamotto until Iron Man’s potential death. He forged a decoy around his neck and opted for illusionary tricks during the battle against Thanos, only conjuring the real Time Stone when he bartered for Tony Stark’s life.
Had he taken out and wielded the Eye earlier to undo Star-Lord’s now infamous moment of anger mismanagement, he would have risked losing the Time Stone to Thanos, who could easily overpower them with the four other Stones on his Gauntlet.
He knew reversing time was no use anyway
Before Thanos’s arrival on Titan, Doctor Strange skimped through over 14 million possible futures, and told his comrades that they only emerge victorious in one. That must mean that he also knew reversing time on his part would’ve been a futile strategy, because even if he could reverse time, Thanos could also reacquire the Stones.
The Time Stone is arguably the most powerful of the Infinity Stones. If not for the fact that the Mind Stone was directly related to the life of a major character, it would have been the last Stone the film’s writers wanted Thanos to obtain. Ultimately, it was still the penultimate Stone collected, showing how impactful the Time Stone is towards storytelling.
On top of that, Doctor Strange, the only manipulator of time we know, was one of the many characters that perished with Thanos’s finger snap. Clearly, the writers are trying to be extra careful by drawing as many boundaries regarding time manipulation.
Time is sure to play an instrumental role in the next Avengers film. Fans are already speculating that the Time Stone is key to reversing the gazillions of deaths in the universe, and until it is removed from Thanos’s Gauntlet, the super villain can easily wield it to undo any of the Avengers’ progress.
We’ll only find out next May when the as-yet-untitled fourth Avengers movie hits theaters. Until then, the only thing we can do is wait for one year of time to pass.