The Spider-Man: No Way Home trailer includes past movie villains coming into the Marvel Cinematic Universe, and one detail may explain why. The first No Way Home trailer finally revealed plot details for the upcoming film. In the movie, Peter Parker (Tom Holland) tries to deal with the repercussions of everyone learning his Spider-Man identity, but it's proving to be too difficult. Parker goes to Doctor Strange (Benedict Cumberbatch) for help, and the Sorcerer Supreme's solution is casting a memory wipe spell on the world. However, Parker doesn't want his family and friends to forget he's Spider-Man, so he interferes with the enchantment. Unfortunately, the interference causes things to go awry, seemingly opening a hole in the Multiverse.
Because Parker messes with Strange's spell, villains from past Spider-Man films are set loose on the MCU. For instance, the trailer reveals Alfred Molina's Doc Ock, an antagonist in Spider-Man 2, making a return. "Hello, Peter," a de-aged Doc Ock says while making a surprising appearance in the trailer. Other villains, such as Willem Dafoe's Green Goblin, Jamie Foxx's Electro, and Thomas Haden Church's Sandman, are also seemingly making a comeback. A brief scene even gives a glimpse of a creature that fans suspect is Lizard (Rhys Ifans) from The Amazing Spider-Man.
There may be a reason why Spider-Man villains are the only ones in the movie. If Strange's spell does backfire like the trailer shows, it's a bit weird that only Spider-Man villains emerge from the rift in the Multiverse. However, a theory (via TikTok) explains it's all due to Peter's DNA. According to the theory, Strange uses Peter's hair in the spell, and Parker's DNA is the reason Spider-Man villains enter the MCU. Strange similarly used Thor's (Chris Hemsworth) hair for a spell in Thor: Ragnarok, so using hair for spells is nothing new for the Sorcerer Supreme. Because Strange creates the spell from Spider-Man's DNA, only villains and characters connected to Spider-Man can enter the MCU.
The DNA theory is plausible. After all, for past Spider-Man villains to come into the MCU, the spell must be connected somehow to Spider-Man. Furthermore, with Loki introducing the concept of variants, Marvel can claim previous versions of Spider-Man are simply variants of the character. Since variants all have some similarities, it makes sense that Spider-Man's DNA would allow a bridge between variant timelines in the Multiverse. Most importantly, it gives Marvel an excuse for why it's only villains from Spider-Man films appearing at the moment.
There could also be other factors at play in Spider-Man: No Way Home that the trailer hasn't revealed yet. Marvel's trailers often include deception, leading fans one way while the movie takes the story in another direction. With this in mind, it's tough to trust anything the trailer reveals. Additionally, nothing is cut and dry when it comes to the MCU's Multiverse. With different variants and timelines in play, the MCU has wiggle room to take the story in any direction it pleases. So while the DNA explanation could very well be true, it also wouldn't be surprising if it's off by just a hair.
