Those who saw “Doctor Strange” noticed one major connection to other Marvel movies: an Infinity Stone. The illustrious rocks are often the focal point of Marvel Cinematic Universe (MCU) films, but that’s a lot of history. The Tesseract, the first of the Infinity Stones introduced, was last seen nearly five years ago. With the Eye of Agamotto adding another artifact to keep track of, it’s time to refresh memories on where the Infinity Stones are and what they do.

The Tesseract: Also known as the Space Stone, the first Infinity Stone introduced in the MCU has the biggest history. The blue cube was first shown in “Thor” and “Captain America: The First Avenger” before finally becoming a huge threat in “The Avengers.” It controls space. The user can teleport, be in two places at once and control where other objects exist. The Tesseract was sent back to Asgard with Thor for safe keeping at the end of the 2012 movie.

Infinity Stones Space Gem The Tesseract, which is the Space Stone, was a huge part of “The Avengers.” Photo: Marvel

The Aether: Remember that red liquid in “Thor: The Dark World”? That was the Reality Stone (it seems the Infinity Stones don’t always have to be actual gems). It gives the user the ability to alter reality, which is a fairly ambiguous quality. Viewers saw it give Malekith (Christopher Eccleston) super strength in “The Dark World,” and it can definitely be used as a powerful weapon. At the end of the 2013 movie, Thor (Chris Hemsworth) sends it to the Collector. “Guardians of the Galaxy” fans know that the Collector’s lair was blown up, so it isn’t clear if he still has the Reality Stone.

Loki’s Scepter: Thanos (Josh Brolin) lent Loki (Tom Hiddleston) the Mind Stone when he sent the Asgardian to Earth for the Tesseract. Not only did Loki fail to get the Tesseract, but his scepter was taken from him by S.H.I.E.L.D. Unfortunately, Hydra managed to get their hands on it and used it to give powers to Scarlet Witch (Elizabeth Olsen) and Quiksilver (Aaron Taylor-Johnson). After Ultron (James Spader) shattered the blue casing, it was just the yellow Mind Stone that was left. It was used to bring Vision (Paul Bettany) to life, and it now resides in his forehead. He has used it to shoot energy blasts out of his forehead, fly and much more. However, even Vision admitted in “Captain America: Civil War” that he isn’t sure of all the Mind Stone’s capabilities.

Infinity Stones Mind Gem Vision (Paul Bettany) keeps the Mind Stone in his head. Photo: Marvel

The Orb: The purple orb that drove the plot of “Guardians of the Galaxy” was the Power Stone. As indicated by its name, it’s a pretty powerful gem. It can be used to destroy a planet, so it’s a good thing Star Lord (Chris Pratt) and the other Guardians managed to keep it out of the wrong hands. They handed it over to the Nova Corps, a police force in Xandar, and they put the Power Stone in a vault in the city.

The Eye of Agamotto: The green stone in Doctor Strange’s (Benedict Cumberbatch) amulet was revealed to be the Time Stone. Obviously, it controls time. Viewers already saw how powerful it can be in newest Marvel movie. At the end of the flick, Strange puts it back on its pedestal at Kamar-Taj in Tibet.

The Soul Stone: Where is the last Infinity Stone? That will likely be revealed sometime before the Avengers face Thanos in 2018’s “Avengers: Infinity War.” Between now and then, “Guardians of the Galaxy Vol. 2,” “Spider-Man: Homecoming,” “Thor: Ragnarok” and “Black Panther” are all set to hit theaters. Whoever finds the Soul Stone will discover that it is a incredibly strong. In the Marvel comics, it has the ability to collect souls, attack souls and look into souls to find the truth.

All of these Infinity Stones could make someone very formidable, which is why Thanos is after them. The purple alien wants to put them in the Infinity gauntlet (seen at the end of “Age of Ultron”), but his intentions are unclear. Does he want to rule the universe or destroy it? Either way, it’ll be up to the superheroes of the MCU to stop him.