When it comes to the ongoing mysteries and unanswered questions of the Marvel Cinematic Universe, nothing trumps the Infinity Stones. The powerful MacGuffins have had a presence in the MCU since the Tesseract in Captain America: The First Avenger, and the collection of all six stones by Thanos will be a huge point of The Avengers: Infinity War. So far there are four confirmed stones, with two – the Time and Soul stones – still unaccounted for. It’s fun to speculate which movies they’ll appear in, but now we’ve got confirmation one of those movies isn't Captain America: Civil War.
This news comes straight from the red carpet premiere of Captain America: Civil War, where ComicBook.com was able to interview the writers of the film, Christopher Markus and Stephen McFeely. McFeely and Markus were asked if any new Infinity Stones would be premiering in the movie, and after a quick glance at each other to figure out if they were allowed to say anything, the duo was able to give a definitive answer. Said McFeely,
I think it's okay to say say it's a stone-free movie.
It seems that the Soul and Time stones are being saved for a later date. Captain America: Civil War is already a packed film, featuring almost every Avenger in addition to new characters like Spider-Man and returning supporting characters like General Ross. Having to deal with the Sokovia Accords and a secret Infinity Stone might be overkill for one movie. It’s better to save the stones for when they can be a bigger focus on the story.
It’s unclear which movie the remaining two stones will next appear in. We’ve seen the Space Stone (the Tesseract from Captain America: The First Avenger and The Avengers), the Mind Stone (from The Avengers, and Avengers: Age of Ultron), the Reality Stone (the Aether from Thor: The Dark World), and the Power Stone (the orb from Guardians of the Galaxy). It’s been rumored that Doctor Strange will feature an Infinity Stone in some capacity, and there is evidence to suggest it may be the Time Stone. Marvel Studios President Kevin Feige has said that the Eye of Agamotto, a mystical relic worn around Stephen Strange's neck, will have the ability to "screw around with time." That sounds like a Time Stone all right.
As for other movies the Infinity Stones can appear in, Thor: Ragnarok seems like a likely candidate. Thor left for space at the end of The Avengers: Age of Ultron to figure out the importance of the Infinity Stones, so it’ll probably factor in some way in his solo film. Another option could be Guardians of the Galaxy Vol. 2. The Guardians are in a good position to run afoul of an Infinity Stone out in space. However, that might get stale, seeing as how the team already dealt with the power stone pretty heavily in their first film.
You’ll be able to see lots of things except the Infinity Stones in Captain America: Civil War, which hits theaters this week on May 6th.