Avengers: Infinity War - Where (And What) Are The Infinity Stones?
3. Reality Stone
Where?
Contained in a liquid form known as the Aether, it's been kept by The Collector (Benicio del Toro) in his museum on Knowhere.
What?
It gives the ability to warp reality itself at will, with great strength, power, and influence over the universe.
In Infinity War:
Rumours suggest that Benicio del Toro will be in Infinity War for a small but important appearance, which in other words means the Collector is going to be paid a visit by Thanos, and that the Mad Titan is leaving with the Reality Stone. Since that's not on Earth, which seems like where the final battle will be taking place, we can perhaps assume that he'll visit the Collector and take the Stone (and probably end del Toro's time in the MCU) before heading down to face the Avengers - this could also be the scene of a run-in with the Guardians (and maybe Thor too).