Avengers: Infinity War is just under six months away, and with Thor: Ragnarok bringing back the Space Stone - and Thanos - the Infinity Stones are about to be more relevant to the Marvel Cinematic Universe than ever.
Given that the first trailer for Avengers: Infinity War shows Thanos filling up his vaunted gauntlet with those very stones, it's high time to take a look back at the history and last known whereabouts of the MCU’s Infinity Stones leading up to Infinity War.
The Space Stone was first mentioned in Iron Man 2 as an unknown element discovered by Tony Stark’s father Howard. It wasn’t until Captain America: The First Avenger that the element’s status as an Infinity Stone derivative was revealed, when it was used by the Red Skull to power advanced weaponry.
The Space Stone is housed in a cube (based on the Cosmic Cube of comic books) known as the Tesseract. Loki stole the Tesseract from S.H.I.E.L.D. in Avengers, combining it with his staff (more on that later) in service of Thanos, before the nascent Avengers sealed the portal it created and stopped Thanos’ invading Chitauri horde.
After Avengers, the Tesseract was housed in Odin’s treasure chamber on Asgard, where it remained until Thor: Ragnarok in which it was stolen by Loki before Asgard’s destruction. Loki is seen seemingly handing the Tesseract to an unseen figure in the Avengers: Infinity War trailer. Thanos is later seen adding it to his Infinity Gauntlet. There's definitely some more context to be learned once the movie is out, but there's a clear line of where it goes.
Remember that staff we were talking about? That staff, which Loki used to mind control his enemies in Avengers, secretly housed the Mind Stone – though that wasn’t revealed until Avengers: Age of Ultron. The staff is also known as the Sceptre.
In Age of Ultron, the Mind Stone was shown as part of the source of Quicksilver and Scarlet Witch’s powers, given to them through Hydra experimentation. Ultron had different plans for the Mind Stone, however, building himself a Vibranium body he planned to power with the stone.
Before Ultron could finish his project, the Avengers interfered, and the body awakened as Vision with a mind based on Tony Stark’s Jarvis A.I. – and the Mind Stone embedded in his forehead (not unlike Adam Warlock and the Soul Stone in comic books). The stone remains in Vision’s forehead - though the Avengers: Infinity War trailer shows it being pried out by the Black Order.
The Reality Stone - also known as “the Ether” - first reared its head as Thor: The Dark World’s McGuffin. The stone, manifested through most of the film as a dark red cloud capable of remaking a world in its wielder’s image, was villain Malekith’s tool to turn Earth into a suitable home for his Dark Elves.
In the wake of Malekith’s defeat, the Ether solidified into its natural gem form. The Reality Stone was last seen being delivered to the Collector by Sif and Volstagg in that film’s post-credits scene. It is not seen in the trailer for Avengers: Infinity War, so as far as we know, the Collector still has it.
The Reality Stone wasn’t the only Infinity Stone to pass through the Collector’s hands, though unlike the Ether, the Power Stone - his second catch - slipped right through his grasp, stolen by Ronan after he failed to take it from Star-Lord.
Housed in a mysterious vessel called the Orb, the Power Stone was the focus of Guardians of the Galaxy, with the villainous Ronan seizing the Stone’s power in direct defiance of Thanos. It was relegated to the care of the Nova Corps after Star-Lord and the Guardians worked together to turn it against Ronan, saving the Nova Corps' homeworld of Zandar.
Thanos is shown wielding the Power Stone in the trailer for Avengers: Infinity War, meaning that at some point he'll take it from the Nova Corps.
In Doctor Strange, the Sorcerer Supreme’s iconic medallion and artifact the Eye of Agamotto was revealed as the Time Stone – an object that Strange was able to wield against Dormammu despite the toll Infinity Stones usually take on mortals.
Strange gave up the Stone at the end of the film, though he was seen wielding it in Thor: Ragnarok, having apparently progressed his skill since his own film. He's still wearing it in the trailer for Avengers: Infinity War.
The Soul Stone is the only Infinity Stone yet to appear on the big screen. As for where it lies, there have been few clues presented on film so far (we know from flashbacks that it's MCU color is probably orange and that's about it).
While Vision’s Mind Stone somewhat mimics Adam Warlock’s comic book relationship with the Soul Stone, Warlock himself has yet to appear – though he was alluded to in the end of Guardians of the Galaxy Vol. 2.
Given that Marvel Studios president Kevin Feige has denied Adam Warlock will debut in Avengers: Infinity War but that this stone would appear in Phase 3, it’s a safe bet we’ll see the Soul Stone before its traditional wielder - with some even speculating it will be revealed in Wakanda in February's Black Panther.
Editor's Note: This article has been updated to reflect new information gained from the Avengers: Infinity War trailer.