Warning: SPOILERS for Avengers: Infinity War are ahead!
Death is common in the Marvel Cinematic Universe, but usually it's the villains or supporting characters who are its frequent victims. Few heroic figures in this franchise have departed to the great beyond, and even fewer have actually stayed there. Pietro Maximoff, a.k.a. Quicksilver, is part of that select group, but three years after we watched him sacrifice himself in Avengers: Age of Ultron, rumor has it that he may be brought back for Avengers 4.
When Thanos snapped his fingers towards the end of Avengers: Infinity War, the combined power of the six Infinity Stones wiped out half of life in the universe, which included many of the MCU's heroes. The surviving Avengers, Guardians of the Galaxy and more will work in Avengers 4 to undo what the Mad Titan wrought, but evidently the concluding Phase Three chapter may also bring back at least one familiar face who was gone before all this craziness, as Sunday Express reports that Quicksilver actor Aaron Taylor-Johnson was "spotted" on the movie's set.
Like his sister Wanda Maximoff, a.k.a. Scarlet Witch, Quicksilver debuted in the MCU during Captain America: The Winter Soldier's mid-credits scene, and he made his full debut in Avengers: Age of Ultron. Both siblings were originally adversaries to Earth's Mightiest Heroes, first serving Hydra and then joining forces with Ultron, but when they learned the megalomaniacal robot wanted to wipe out all life on Earth, they switched allegiances and fought alongside the Avengers during the Battle of Sokovia. Quicksilver's super speed came in handy with alerting Sokovia's citizens of the attack and taking out many of Ultron's drones, but he died when he intercepted bullets that were about to hit Hawkeye and a kid the archer was protecting.
Assuming that Thanos' Infinity snap didn't accidentally bring a few people back to life, one would imagine that either Quicksilver's possible return in Avengers 4 is either due to a different type of resurrection or that we're seeing him in a different capacity. While Marvel is keeping tight-lipped on what's in store for Avengers 4, leaked set photos from last year seemed to indicate that time travel would play a role in the movie, although that's been called into question since directors Joe and Anthony Russo implied that the recreation of certain major events is actually due to Tony Stark's BARF technology. Still, if the Battle of Sokovia is being "revisited" in some form or fashion, then it would make sense to see Quicksilver there.
It's also possible that rather than being completely dead, the heroes who faded away post-Snap in Avengers: Infinity War have actually been transported to another reality where the laws of time and space work differently. Perhaps while in this realm, Wanda will somehow see/interact with Pietro, which might mean that we'll be visited by other truly deceased characters during Avengers 4.
Avengers 4 hits theaters on May 3, 2019, so stay tuned to CinemaBlend for continuing coverage on the Marvel blockbuster. In the meantime, if you're dying for a little Quicksilver cinematic action sooner, you can see Evan Peters' version return when X-Men: Dark Phoenix is released on February 14, 2019.