The Batman Serum Fan Theory That's Lighting Up Reddit

Warning: This article contains spoilers for "The Batman"

Robert Pattinson's long-awaited rendition of the beloved Dark Knight is finally here in the form of director Matt Reeves's nearly three-hour-long movie epic "The Batman." The theatrical film, which sees an early-career Batman take on a mysterious serial killer called The Riddler (Paul Dano) with the help of the feline-loving thief Catwoman (Zoë Kravitz) and Police Lieutenant Jim Gordon (Jeffrey Wright), has already become a massive critical and commercial success, receiving plenty of rave reviews and recouping over half of its $200 million budget in its opening weekend alone.

Of course, many fans of the comic book character are also excitedly discussing the movie in its entirety, and a fair few have taken to social media and other online forums to talk about what they liked or didn't like and dissect different plot points. Some contention over a few ambiguous plot threads within the movie has already arisen, such as a debate surrounding whether or not The Riddler actually figured out Batman's secret identity. However, there's one particular question of note that's still playing on the minds of many viewers: just what exactly was the mysterious green liquid Batman injected himself with near the end of the movie? A good few bits of speculation that delve into the storied history of Batman and his laundry list of villains in the comics have emerged already, but one interesting new theory may actually prove to be the definitive answer to this burning question. 

Viewers of "The Batman" will recall a sequence close to the film's conclusion where Batman is battling The Riddler's followers as they attempt to carry out a mass shooting. Batman is very nearly killed by one of the gunmen, but is saved by Catwoman in the nick of time. Unfortunately, Catwoman is quickly attacked by another one of the villains and a winded Batman helplessly watches as she almost dies in front of him. It's then that the hero pulls out a strange vial of bright green liquid which then he injects into himself. In a sudden fit of rage, Batman springs up and attacks the criminal, ruthlessly beating him until Gordon and Catwoman finally get him to calm down.

It's never stated in the movie just what exactly this green substance is, which has led to a great deal of fan speculation over its true contents. Some have theorized that the serum was nothing more than liquid adrenaline, while others argued that its suspect color and obvious significance suggested that it was something more unique. The prevailing theory is that the serum was actually a nod to Venom, a strength-inducing serum that Batman once became infamously addicted to in the comics and which serves as the serum that gives the hulking Bat-villain Bane his strength. While this theory does indeed have its merits, there's another intriguing fan theory making the rounds on Reddit that offers an alternative comic-minded explanation to the liquid.

A new theory posted by Reddit user u/weirdking77179 on the r/FanTheories subreddit suggests that the serum is actually a dose of water from the mythical Lazarus Pit in DC Comics lore. The pit, often guarded by the villain Ra's al Ghul and his League of Assassins, is famous in the comics for its regenerative properties, being able to restore strength and even bring the dead back to life. This theory suggests that Pattinson's Bruce Wayne trained with Ra's al Ghul prior to becoming Batman and eventually betrayed the villain, stealing a small portion of the Lazarus Pit water.

The theory certainly has some weight to it. Some past iterations of Batman trained with Ra's al Ghul before returning to Gotham City, such as in Christopher Nolan's film "Batman Begins." The effects of the Lazarus Pit has also been showcased in different media, such as in an episode of the animated series "Batman Beyond," where an older Bruce Wayne bathed in the pit and came out stronger, but also in a deep fit of rage. Sound familiar?

This theory could definitely be the answer to the mystery of the green serum in "The Batman," but again, nothing has been confirmed yet. With the rumor that Pattinson's Batman will return for a film sequel in the near future, it seems likely that the entire truth will eventually be revealed in a future character outing. For now, fans will simply have to wait and see.