Quick Marvel pop quiz! Off the top of your head, can you place each of the Infinity Stones within the Cinematic Universe right now? Perhaps we should back this up and start with the basics: Can you even explain what the Infinity Stones are?
Here's how the Collector (Benicio del Toro, in all his white-eyebrowed glory) summarized them in Guardians of the Galaxy: "Before creation itself, there were six singularities. Then the universe exploded into existence and the remnants of these systems were forged into concentrated ingots."
So, that's…vague, but all you need to know is there are six total and they have been popping up as MacGuffins in the MCU since before the Avengers first assembled. When Thanos (Josh Brolin) threw on that gold glove in the mid-credits sequence of Age of Ultron and growled, "Fine, I'll do it myself," he was setting off a string of events that will culminate in Avengers: Infinity Wars in 2018. Before then, peruse this thorough field guide to the Infinity Stones.
The Space Stone
The Space Stone might be the most passed-around Infinity Stone in the entire MCU, though it's better known as the Tesseract. First appearing in Captain America: The First Avenger, it was used by German S.S. officer Johann Schmidt (aka Hugo Weaving's nefarious Red Skull) to create weapons for the Nazis. Years later, S.H.I.E.L.D. mistakenly used it to open a portal in space that allowed Loki (Tom Hiddleston) to come to earth. Ultimately, Thor returned the Space Stone to Asgard at the end of The Avengers, where it would be under the protection of Heimdall.
The Mind Stone
The Mind Stone also factored into the aforementioned Tesseract-allowing-Loki-to-try-to-take-over-earth incident, as Loki's scepter contained the stone within it. It was a gift from Thanos that Loki used to mind-control Hawkeye (Jeremy Renner). Ahead of Age of Ultron, HYDRA came into possession of the scepter and used it to give the twins their powers, and Ultron ultimately used it to create Vision (Paul Bettany). That's where it currently resides. The gem is embedded in Vision's forehead and grants him a whole bunch of superpowers. (Like shooting laser beams!)
The Reality Stone
Remember that evil-looking red syrup that Jane Foster (Natalie Portman) stumbled upon in a random warehouse in Thor: The Dark World? And then she decided to just touch it? And it possessed her? Yep! Infinity Stone! The Aether is a weaponized version of the Reality Stone, used to...uh, cover every realm in darkness? That's what the Dark Elves wanted to use it for, at least. Anyway, in the end, the Asgardians shipped the Aether off to the Collector to house in his museum, which was subsequently destroyed by the Power Stone. Basically, wherever Howard the Duck is, the Reality Stone likely is too.
The Power Stone
Whereas everything about the Reality Stone is fairly nebulous, the Power Stone is all there in the title: It "gives the owner access to all power and energy that ever has or will exist," as exhibited in the Collector's Intro to Infinity Stones 101 lecture, when it is used to annihilate entire planets. In Guardians, Peter Quill (Chris Pratt) inadvertently came into possession of the Power Stone within the Orb. After using it to destroy Ronan the Accuser, the legendary outlaw called Star-Lord -- maybe you know him by that name -- bequeathed it to Irani Rael (Glenn Close), who locked it away with the Nova Corps on Xandar.
The Time Stone
Throughout Doctor Strange, the future Sorcerer Supreme (Benedict Cumberbatch) uses the Eye of Agamotto to manipulate the space-time continuum, speeding time up and slowing it down, turning time back and creating time loops. Fans had been speculating that the green glow might belong to none other than the aptly named Time Stone, which Wong (Benedict Wong) finally confirmed in the final moments of the film, offhandedly warning Strange that he wouldn't want to walk around wearing an Infinity Stone. Instead, the Eye and the Time Stone within it are safe at Kamar-Taj. For now.
The Soul Stone
That leaves one Infinity Stone whose location is TBD. In comic books, the Soul Stone can be used to manipulate both the living and dead and is capable of stealing and storing souls. It’s often wielded by Adam Warlock, a character yet to be introduced into the MCU. (Although his cocoon did appear as an Easter egg in Guardians.)
There are just two movies ahead of Avengers: Infinity Wars where the soul stone could surface: Thor: Ragnarok and Black Panther. Director James Gunn has confirmed there will not be any Infinity Stones in Guardians 2 and Marvel likely wouldn't relinquish one to Spider-Man: Homecoming or any of the Netflix Cinematic Universe shows. Or Agents of S.H.I.E.L.D. (LOL!)
Then again, the Soul Stone was the final gem Thanos collected in the comics, so perhaps it won't make its big-screen debut until the events of Infinity Wars. Finders keepers! Losers get their souls snatched!