Did Thanos travel back in time at the end of Avengers: Infinity War? In one key scene, Thanos spoke to Doctor Strange and explained his insane vision. "With all the six stones, I could simply snap my fingers, and [trillions] would all cease to exist," he told Strange. "I call that mercy." A horrified Strange asked what would come next, and Thanos gave a startling response. "I finally rest, and watch the sunrise on an grateful universe." This version of Thanos dreamed of the day when his dreadful mission would finally be fulfilled, and when he could retire in peace.

Avengers: Infinity War's ending saw Thanos achieved his insane goal. He snapped his fingers and erased half the life in the universe. Then, true to his word, Thanos retreated from the cosmos and disappeared, becoming little more than a simple farmer. That idea was actually lifted from the original comics, where Jim Starlin's Infinity Gauntlet miniseries ended with Thanos apparently embracing a simple life.

Read More: Infinity War’s Thanos Isn't Really Marvel’s Thanos

But just where did Thanos go? Or is it possible the correct question is - when? It's actually possible Thanos has actually sought to evade anyone who would seek revenge upon him by using the Time Stone.

Thanos is on Titan At The End of Infinity War

Although Avengers: Infinity War only gave viewers a brief glimpse of Thanos's retirement, the lighting and general color scheme strongly implied that he'd headed back to his homeworld, Titan. This has recently been confirmed by concept artist Pete Thompson, who's published some beautiful Avengers: Infinity War concept art on his portfolio website, including a landscape of the final scene labeled "Titan Thanos farm (post-production) Pre Production by Chris Kessler". It's a stunning design, clearly inspired by the famous Banaue Rice Terraces of the Philippines.

But there's a problem with this. Thanos has clearly retired to a place of peace and tranquility, believing his horrific mission to be finally done, and the Titan we saw in Avengers: Infinity War certainly wasn't a place of peace. According to Thanos, it had fallen prey to the ravages of overpopulation, and some sort of disaster - likely a food shortage - had led to the extinction of his race. Significantly, everything we saw of Titan's surface lacked any hint of vegetation. There was no evidence of nature reclaiming the barren world; it was as though Titan had been completely sterilized of life. Over the course of the film, this just got worse; Thanos tugged a moon out of orbit around his homeworld. That action would have caused fluctuations in his homeworld's gravitational field, probably triggering earthquakes or floods.

Even stranger, the kind of environment Thanos has retired to doesn't just come about naturally. The Banaue Rice Terraces look the way they do because they've been cultivated for generations by the Ifugao people, who consider themselves to be caretakers of the land. In just the same way, this kind of terraced effect is only possible if someone has actually been looking after the farmland. And yet Thanos claims his homeworld has been unpopulated for untold years. We essentially have two versions of Titan; the one we saw at the beginning of the film, and the one Thanos retires to at the end. The two simply don't go together.

Page 2 of 2: Has Thanos Traveled Back in Time?

Has Thanos Traveled Back in Time?

It's important to remember that Thanos doesn't just possess the Space Stone; he also wields the power of the Time Stone. As a result, he can travel anywhere in the universe - and, significantly, anywhen. If his entire quest was motivated from trying to save Titan, with its destruction the making of the man, then it would only make sense for him to return to a time before it was a gravity-messy hellscape.

That could mean the Titan he finds himself on at the end isn't restored, rather it's the planet from before disaster struck. Presumably, Thanos has settled down in a remote corner of his world, one populated only by farmers, explaining why the land is clearly cultivated but he doesn't impact the timestream. Every day, when Thanos stared out at the sunrise, he'd experience a strangely bittersweet emotion; he'd know that all this beauty would ultimately pass away, but on the other hand he'd always be able to remind himself that he had - according to his own insane logic - "saved" the rest of the universe.

Titan would essentially be sacrificed in order to ensure life survived. Given he did a similar, more personal action with Gamora and accepts his victory cost "everything", it's a believable form of solitude.

This Theory May Enable the Avengers' Victory

If this theory is correct, it may well give the Avengers an opportunity to defeat the Mad Titan. It's generally believed the Avengers will use time-travel in an attempt to undo or avert the "snap". Were he in the present day, Thanos would surely discover what Earth's Mightiest Heroes were trying to do. By living in the distant past, though, he's removed himself from the rest of the universe; he'd only learn of the Avengers' plan when he began to notice subtle ripples of change in time. By then, it may well be too late to stop the heroes.

Depending on the MCU's model of temporal mechanics, this theory may actually also help explain Doctor Strange's endgame plan. This implies Thanos was always destined to win; that he was always fated to return to his world's heyday, to settle in this distant corner of Titan and watch the sun rise. The victory could only come after that - and the massive sacrifice that came with it.

Is This Thanos Theory True?

Thanos traveling back in time at the end of Avengers: Infinity War is an attractive theory, not least because it explains the strange contrast between these two versions of Titan. But it's important to note that there are alternative explanations. The most obvious is that Thanos could have simply used the Reality Stone to recreate the Titan of his childhood. That would neatly explain why the land is clearly cultivated, and yet we don't see any sign of other inhabitants.

It all rests on the nature of the story Marvel want to tell. It's already clear Avengers 4 will principally be a time-travel story, but the more elements of time-travel you bring into a single narrative, the more you risk complicating your tale to the point it loses all semblance of logic and consistency. Marvel could take this approach, but they may not be wise to do so, because they'd just be adding another layer of complexity to a story that already promises to be full of ideas and characters.

Whatever the truth may be, of one thing we can be certain; Josh Brolin's Thanos will return, meaning the Mad Titan will somehow have to learn that the Avengers are attempting to put the world to rights. That's the only reason Thanos would leave his retirement; if he believed all he had accomplished was actually threatened.

More: Avengers 4 Theory: Gamora Is Still The Key To Beating Thanos

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