It’s likely that Breaking Bad could be a prequel to The Walking Dead, thanks to the shows’ plot similarities, corresponding timelines and continuity.

In 2016, the oddly convincing theory that Breaking Bad was a prequel to The Walking Dead started circulating on the Internet. Some interesting observations led to the belief that Breaking Bad was directly connected to The Walking Dead. While it seems impossible for Walter White’s meth-peddling power trip to have anything to do with Rick Grimes’ apocalyptic story, there have been some persuasive arguments to support the Breaking Bad/Walking Dead theory.

In The Walking Dead Season 2, Episode 2, “Bloodletting,” when T-Dog was infected, Daryl Dixon came to the rescue with a veritable pharmacy in his bike bag. Some of its contents were from his brother Merle’s drug stash. He discovered some blue crystals at the bottom, tucked away from plain sight, that bore a striking resemblance to “Blue Sky,” the street name coined for the 99.1% chemically pure crystal methamphetamine manufactured by Walter and Jesse Pinkman.

Are Breaking Bad and The Walking Dead Connected?

Fans have based the theory that Walter White was inadvertently responsible for the undead epidemic on the presence of blue meth within The Walking Dead. For the uninitiated, meth can appear either clear or opaque but is always a shade of white. Blue meth was specifically created for Vince Gilligan’s series — therefore the reasonable conclusion would be that the two universes are connected.

To add more credence to this claim, The Walking Dead, Season 4, Episode 12, “Still” shed some light on how Merle Dixon obtained his narcotics. According to Daryl, his dealer was “A janky little white guy. A tweaker [junkie],” who once pulled a gun on him and said, “I’m gonna kill you, b*tch.” To Breaking Bad fans, that physical profile perfectly matches Jesse, who was notorious for his use of the curse word throughout the series and Jesse’s post-show adventure El Camino.

Besides that glaringly obvious connection, the red 2009 Dodge Challenger with black racing stripes that Walter bought for his son Walter Jr. and subsequently blew up appeared in a handful of The Walking Dead installments. Steven Yeun’s character Glenn Rhee famously took it for a ride, and Glenn was the name of the salesman that Walter returned the car to in Breaking Bad. Viewers never saw his face, so it would be a reach to assume that he was the same person, but it remained an interesting similarity.

How Gus Fring Fits Into the Breaking Bad/Walking Dead Theory

Netflix addressed if Breaking Bad and The Walking Dead are connected in an official YouTube video, wherein the streaming service explained the speculation that Walter’s blue meth caused the zombie pandemic. However, alongside other small details that overlap between Breaking Bad and The Walking Dead, the video also mentions Gus Fring. He was a Chilean-American major narcotics distributor in the Southwestern United States who used legitimate businesses like Los Pollos Hermanos as a front for a vast drug operation.

Gus was the main antagonist of Breaking Bad and became the employer of Walter and Jesse. He and Walter fought like cats and dogs throughout the series, which could mean that Walter’s production of blue meth would be less controlled and possibly tainted the more that he and Gus butted heads. And that, in turn, leads to an interesting idea regarding Gus’s gruesome fate.

Was Breaking Bad’s Gus the First Walking Dead Zombie?

Netflix cleverly pointed out that Gus (played by Kaleidoscope star Giancarlo Esposito) ended his run on Breaking Bad by literally “walking dead.” After an explosion left him without half of his face, he still walked out of his hospital room before dropping dead. The scene supported the idea that before Gus’ demise, he faced his mortal enemy Hector Salamanca with the first batch of unstable blue meth. When the bomb exploded, he became the first “zombie,” also known as The Walking Dead‘s Patient Zero.

This part of the theory requires viewers to invent their own motives, moments and opinions that never appeared within Breaking Bad to make it plausible. For example, Gus’ refusal to work with “junkies” and the cold, calculating personality which made him so successful and ruthless suggested he would never risk taking drugs and upsetting his steadfast conscience. However, it’s an interesting idea, even if it does have some holes in it.

Bearing this theory in mind, AMC could set up a Breaking Bad and Walking Dead crossover if both respective universes continue to churn out spinoffs. Or the whole concept could just be hopeful fans desperately peddling ideas due to a fond love for both shows. Either way, the connections between AMC’s two most popular series are undoubtedly uncanny.