The Family Twist in ‘Joker’ May Not Be a Twist at All (2024)

Spoiler warning: If you haven't yet seen Joker and plan on doing so, now's your chance to stop reading. The rest of this story will be littered with movie plot points and spoilers. You have been warned!

• In Joker, Thomas Wayne (Batman's father) and Penny Fleck (Joker's mother) are key characters.
• Penny claims that Thomas is actually Arthur's father.
• The movie wants you to guess for yourself who's telling the truth.

Within the world of Joker, the line between reality and delusion is delicately toed throughout the movie's two-hour runtime. Notably, viewers are led to believe that Arthur Fleck (Joaquin Phoenix), who becomes the titular Joker, is in a romantic relationship with his neighbor Sophie Dumond, played by Zazie Beetz. This is later revealed to be all inside his head.

But perhaps the movie's biggest twist is the possible connection between Arthur and Bruce Wayne, as in his arch-nemesis Batman. Earlier in the movie, Arthur notices that his mother, Penny Fleck (Frances Conroy), is obsessed with a local businessman named Thomas Wayne (played by True Detective's Brett Cullen). When he opens a letter she's addressed to him, he sees a handwritten note that describes Arthur as Thomas' son, suggesting that the Joker and Batman are half brothers. But is that really true?

According to Penny, Arthur was born of an affair she had with Thomas when she worked for him. She said in a flashback that Thomas' wealth, power, and influence helped to produce the claim and paperwork that Arthur was adopted.

But according to Thomas, Penny was mentally ill when she worked for him, and the claim that their sons are brothers is a delusion. At one point, Arthur does visit Arkham State Hospital and reads his mother's file, which says that she adopted him as a child and an abusive boyfriend took advantage of both her and Arthur when he was an infant/toddler.

Thomas Wayne was originally going to be played by Alec Baldwin, but Baldwin dropped out early on in Joker's production. Instead, Cullen stepped in and did an admirable job. Cullen spoke with The Hollywood Reporter about his character, and the potential twist regarding Arthur/The Joker.

"I was very surprised when I read the twist," he said. "I went to [Director Todd Phillips] and asked, Are we playing this the way I think we’re playing this? Todd responded with, What would be a compelling reason for the Joker to hate Batman so much? The idea that the Joker is an illegitimate child that didn’t get anything from the Wayne family is a very compelling motivation for his character’s hatred. This movie makes you feel for Arthur, when you see him struggling with his mother. And she’s saying, Go see Thomas Wayne, he’ll help us. He’s a good man. It’s gut-wrenching."

Whether Arthur is actually a son of the Wayne family or not, Cullen makes a compelling point about Arthur, and his motivation toward Batman down the line. Whether he actually is Thomas' son, and whether he believes he's Thomas' son or not, the motivation of him feeling rejected by the Wayne family make his motivation to battle an eventual Batman make a ton of sense.

People on Twitter have felt a similar way after seeing the movie. Whether or not Thomas is actually Arthur's father, his coldness and rejection played a major part in turning Arthur from an unstable loner into a monster.

At the end of the day, there's more evidence that Thomas is telling the truth. Not because he's a particularly upstanding person—he's presented as the antagonist, and a quasi-villain of the movie—but when Arthur goes to the Wayne estate and meets Bruce and, eventually, Alfred, even Alfred says that Penny was unhinged.

Now, Joker presents a different reality, so we can't be certain that this version of Alfred (played by Douglas Hodge) shares the same noble and loyal nature that the Alfreds played by Michael Caine and Jeremy Irons in the past. But given the history of the character, it's enough to convince us that's the truth—at least for now.