The Discomfort Bomb
Explanation
The Joke
Batman and Robin are in a classic superhero scenario, needing to clear Central Station before the Joker arrives. Batman suggests using "the discomfort bomb." When Robin asks what that is, Batman explains: "When the timer hits zero, your grandpa appears and starts talking about his views on race."
The final panel shows an elderly man in a public space loudly sharing his opinions while bystanders look on in horrified discomfort. Batman notes that the grandpa has a hearing aid and does not realize how loudly he is talking.
The Humor
The joke operates on the universal experience of having an elderly relative who holds outdated or offensive views on race and shares them loudly and publicly, creating excruciating social discomfort for everyone within earshot. By reframing this common family embarrassment as a superhero weapon -- a "discomfort bomb" -- the comic highlights just how powerfully uncomfortable these situations are. The fact that it could clear an entire train station suggests the social discomfort is more effective at dispersing crowds than any actual weapon.
The detail about the hearing aid adds an extra layer: the grandpa does not even realize how loud he is being, which makes it impossible to discreetly shut him down. This is a recognizable real-world detail that makes the scenario even more painfully relatable. The comic also works as a parody of Batman's famously elaborate and specialized gadgets, suggesting that even the Dark Knight would resort to weaponized social awkwardness.
References
The comic is a parody of Batman and Robin from DC Comics, featuring their classic dynamic of Batman explaining a plan while Robin asks questions. The setting of clearing a location before the Joker arrives is a standard Batman plot device. The "discomfort bomb" is a play on Batman's tradition of having a specialized gadget for every situation (Bat-shark-repellent, etc.).