WARNING: The following contains spoilers for WandaVision Episode 6, "All-New Halloween Spooktacular!" now streaming on Disney+.

Episode 6 of WandaVision, "All-New Halloween Spooktacular!," continued to build on Episode 5's surprise ending, raising even more questions about Evan Peters' Pietro and what he's after. Wanda's attempts to casually interrogate her brother didn't get her anywhere either, with Pietro quickly catching on to what she was doing. He did, however, mention a darkly funny incident about one of their Halloweens in Sokovia as children, resulting in a flashback that may have subtly nodded to the X-Men and Fantastic Four's origins in the Marvel Cinematic Universe.

While the Sokovia flashback was mostly focused on a humorous gag involving Wanda and Pietro getting a dead fish for Halloween, there were also two Soviet propaganda posters featured prominently in the background. Such posters date back to the Soviet Union's early days in the 1920s and were initially designed to glorify the triumphs of the Red Army. They typically combined simple designs with bold font, which allowed them to remain accessible to those who were illiterate. Later, during World War II, they evolved to focus on other military subjects and often featured caricatures of the Soviet Union's enemies.

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WandaVision Soviet Posters

The Soviet posters on WandaVision have very pointed vibes, with one of them alluding to "Children of the Atom" and the other celebrating the Soviet Union's progress in the Space Race from the mid-20th century. These could be subtle allusions to the X-Men and Fantastic Four's respective origins in the MCU, paving the way for their proper debut down the line. This wouldn't be the first time the show dropped what appeared to be a reference to the Fantastic Four either, with Monica Rambeau saying on multiple occasions she knows an unnamed aerospace engineer who many viewers suspect will turn out to be Reed Richards.

What's also interesting is that Pietro remembers these posters looking new, despite their old aesthetic. Although their dates aren't specified on WandaVision, they seem to be from the 1960s or '70s, just after or during the Space Race. The problem is, the MCU's Wanda is believed to be a child of the '90s, meaning she wouldn't have been alive when the Sokovian Halloween scene took place. If so, this constitutes further proof that Pietro is actually Quicksilver from Fox's X-Men universe, as he was still a teenager during the events of X-Men: Days of Future Past, which took place in 1973.

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WandaVision Episode 5 Evan Peters

As Wanda noted, this isn't how she remembered things, but it would explain the disparity indicated by the time period of the posters in this WandaVision scene. Then again, Quicksilver was living in the United States and going by Peter in Days of Future Past, not Eastern Europe or any former Soviet nations like Sokovia. So even this is suspect and suggests Pietro is actually an imposter trying to pull a fast one on Wanda. He might've even encountered a version of Quicksilver from another Marvel universe before meeting Wanda, which would explain why this version of the character only partly aligns with the one from Fox's X-Men movies.

It's anyone guess who Pietro really is, if not who he claims to be, with popular suspects including Nightmare, Loki and, yes, Mephisto. Regardless, by bringing Peters into the fold, WandaVision has opened the door for other actors from Fox's X-Men films to show up in the MCU while also laying the groundwork for mutants in the franchise. And with Jon Watts' Fantastic Four MCU reboot confirmed to be moving forward, odds are these Fantastic Four teases will similarly be paid off, one way or another.

Written by Jac Schaeffer and directed by Matt Shakman, WandaVision stars Elizabeth Olsen as Wanda Maximoff/Scarlet Witch, Paul Bettany as Vision, Randall Park as Agent Jimmy Woo, Kat Dennings as Darcy Lewis, Teyonah Parris as Monica Rambeau and Kathryn Hahn as Agnes. New episodes air Fridays on Disney+.

KEEP READING: A WandaVision Guide: News, Easter Eggs, Reviews, Recaps, Theories and Rumors