(Note: This post contains a whole bunch of spoilers for “Avengers: Infinity War” — particularly the end. If you somehow are both a person who has not seen the movie and also a person who is concerned about spoilers, well, you probably ought to leave.)

For fans of the Marvel Cinematic Universe, the question on everyone’s mind is about how “Avengers 4” is going to resolve the conflict with the incredibly powerful supervillain Thanos in “Avengers: Infinity War.” That has led to all kinds of speculation and fan theory development.

Fans have guessed at all kinds of ways the MCU might deal with Thanos (Josh Brolin) and his big plan in “Infinity War”: Gather all six of the all-powerful Infinity Stones, and use them to reshape the universe by instantly causing half of its life to cease to exist. The end of “Infinity War” is something of a cliffhanger, but the conclusion is a harsh one: Thanos succeeds, and people everywhere turn to dust. That includes many of the MCU’s heroes.

Also Read: The 8 Wildest 'Avengers: Infinity War' Fan Theories Out There (Spoilers)

The question now is, what happened to those people, and how might the remaining heroes get them back and stop Thanos from being all-powerful? There are a lot of potential answers, but one that has gone largely unexplored is that the Infinity Stones themselves might have a say in the future of the MCU.

In fact, several of the Marvel movies, and specifically “Infinity War” itself, have suggested that the stones are more than powerful artifacts: they’re actually alive and have their own desires and even actually do things. And they might have their own agenda apart from what Thanos has done with them.

The MCU has been slowly laying suggesting the possibility that there is more to the Infinity Stones for some time now. It started with the appearance of the Aether, the form of the Reality Stone, which popped up in “Thor: The Dark World” in 2013. In that movie, the Aether is a liquid that binds to lifeforms, giving them insane power but also sucking the life out of them. It’s described not as a tool, but as a parasite, with a will of its own.

Also Read: Everything That Happened in 'Avengers: Infinity War' May Have Been Part of a Cosmic Test

In “Avengers: Age of Ultron” in 2015, the Avengers discover the Mind Stone, which was hidden in Loki’s scepter in “The Avengers” in 2012. Tony Stark (Robert Downey Jr.) and Bruce Banner (Mark Ruffalo) scanned the stone to create Ultron (James Spader), and when they did, found that it was much more than just a magic rock — they described it being a powerful computer, but also possibly sentient.

That sentiment has continued since the Mind Stone became part of the hero Vision (Paul Bettany). The Mind Stone sits in his forehead and is both part of what makes him who he is, and also a separate “entity,” as Vision describes it. In “Infinity War,” the Mind Stone is even trying to communicate with Vision: he explains to Wanda Maximoff (Elizabeth Olsen) that it is warning him about Thanos and his Black Order, who are hunting the stone — seemingly indicating that the Mind Stone didn’t want Thanos to have it.

Later in “Infinity War,” we get a couple more instances that suggest the Soul Stones are more than just stones. When Thanos and Gamora (Zoe Saldana) head to Vormir to find the Soul Stone, they meet its keeper: the Red Skull (Ross Marquand), a villain last seen fighting Captain America (Chris Evans) back in 1944 in “Captain America: The First Avenger.” Cap’s fight with the Skull ended with him basically being sucked through a portal created by the Space Stone — at that time, disguised as the artifact known as the Tesseract.

Also Read: How Will 'Captain Marvel' Play Into That Wild 'Avengers: Infinity War' Ending?

The Red Skull explains that he’s now the keeper of the Soul Stone, and that the Space Stone “cast me out,” forcing him into the role. Because of that, he basically seems enslaved to the Soul Stone. The Skull says he’s doomed to “lead others to a treasure I can never possess,” which sure sounds like both the Space Stone and the Soul Stone are in control and even coordinating with each other.

Finally, there’s the Soul Stone itself, which requires a sacrifice of the person who would possess it: a soul for a soul, the Red Skull explains. Thanos is made to give up the person he loves most — Gamora — in order to get the Soul Stone.

All of that suggests there’s a lot more to the Infinity Stones than we’ve yet learned, and it’s clear the MCU means for them to be more than just artifacts, but possibly living beings with wills of their own. This slowly building thread, like a lot of things in the MCU, would make sense as coming to a conclusion in “Avengers 4.” It’s an aspect we haven’t seen come into play yet, but we know that at least one stone, the Mind Stone, seems opposed to Thanos. We could see the will of the Infinity Stones themselves become a part of the story going forward.

Also Read: 'Avengers: Infinity War' -- That Crazy Ending Was Part of Doctor Strange's Plan

It’s hard to say exactly what that could mean or how it would work, in terms of the stones trying to accomplish their own agenda. Is Thanos a part of what they want for themselves or the universe, or a roadblock to it? And what’s more, it doesn’t seem as though all the stones are necessarily aligned in purpose, if they do have one. The Reality Stone as the Aether, for instance, seemed to want to consume life. The Mind Stone, on the other hand, seems more potentially benevolent (after all, in “Age of Ultron,” Vision was able to pick up Thor’s hammer Mjolnir, which only those who are worthy could lift). And the Space and Soul stones seem to be working together for some unknown purpose.

One thing is for sure: Thanos has never considered that the Infinity Stones might be more than tools to be possessed, and if he has, well, his respect for life isn’t exactly his best feature. He’s not likely to care much, even if he does know. But the stones may well take issue with how Thanos chooses to use them, and they might not be too impressed with the way Thanos is willing to murder everybody.

We’ve spent a lot of time over the past few weeks digging through the details to try to figure out what’s coming not just in “Avengers 4” but also “Captain Marvel” and “Ant-Man and the Wasp.” We have come up with a pretty solid guess about what is involved in the one future Doctor Strange saw in which the Avengers defeat Thanos. Click here for our deeper look into how “Captain Marvel” might impact that distressing plot twist. at the end of “Infinity War.” Click here for our look at what “Ant-Man and the Wasp” might have to do with all this. Click here for our discussion of the whole Vision situation and whether he’s really dead. And right here is our discussion of what “Infinity War” could mean for the future of The Hulk. Here’s a rundown of who else might be responsible for a cosmic game at the heart of “Infinity War” — the Collector. And, finally, here’s our run-down on how the comic book version of these events played out.