Abby Ryder Fortson's Cassie Lang is one of the best parts of Peyton Reed's first two "Ant-Man" films. 2015's "Ant-Man" introduces Cassie as an eight-year-old ball of energy who sees nothing but the best in her father, Paul Rudd's Scott Lang, even when the rest of the world dismisses him as an ex-con. She's also weird in a way that rings believable for a kid, nerding out over the "ugly" bunny doll Scott gifts her on her birthday.

The next time we see Cassie in 2018's "Ant-Man and the Wasp," she's grown up enough to have some thoughts on her dad's quasi-romantic relationship with his work buddy, Evangeline Lilly's Hope van Dyne, but not so much as to strain credibility. These scenes rely heavily on Rudd and Fortson to work. Fortunately, their strong chemistry is more than enough to fully sell this father-daughter dynamic despite limited screen time.

Emma Fuhrmann would replace Fortson as Cassie for the character's third appearance in the Marvel Cinematic Universe in 2019's "Avengers: Endgame." This, as you probably recall, was to account for the time that passed between Scott getting stranded in the Quantum Realm at the end of "Wasp" — due to his companions in the everyday realm getting "dusted" by Thanos — and his return five years later in "Endgame." (We thank you for your services, anonymous rat.)

Scott and Cassie's reunion in the movie was brief yet deeply emotional, and it boded well for Fuhrmann reprising Cassie in the third "Ant-Man" film … which is why it came as a shock when it was announced she wouldn't be back. Instead, Kathryn Newton assumed the role of Cassie for Reed's threequel "Ant-Man and the Wasp: Quantumania." Why? It was partially a matter of the character's age, but there's more to it than that.

Not Everyone Can Hang With Paul Rudd

In the audio commentary included with "Ant-Man and the Wasp: Quantumania" for its release on the home media market (via The Direct), Peyton Reed noted Cassie is 18 years old in the film (making her about two years older than Emma Fuhrmann's iteration). Calling Kathryn Newton "an actor who I have admired for a long time," Reed explained that his main concern was finding someone for the role "who could really hang with Paul Rudd and sort of not be left in the dust." He added:

"She's gotta be sharp, and quick, and funny. And also, [Newton] is an athlete. She's a world-class golfer. She has the physicality for the role."

In his defense, you don't get the impression Reed is deliberately trying to slight Fuhrmann or suggest she isn't capable of being these things. He merely seems excited about working with Newton, an actor who had previously displayed her comedy chops in films like "Blockers" and especially Christopher Landon's great body-swap slasher horror-comedy "Freaky." Newton's turns as the moody teen daughters in the TV dramas "Halt and Catch Fire" and "Big Little Lies" had also shown she was up for capturing the more serious side of the teenage experience — that desire to pursue your ambitions while carving out your identity as an adult separate from that of your parents.

Speaking on the audio commentary with Reed, "Quantumania" writer Jeff Loveness suggested this was another factor that went into Newton's casting for the film:

"And just someone who can seem like Scott Lang's daughter. You know, what does she pick up from him? What does she go against? She's got the heart of Scott. She's also got a bit of that sense of humor, a bit of that messy quality."

Kathryn Newton Innocent

Not long after "Quantumania" opened to unflattering reviews (more on that soon), Abby Ryder Fortson starred in "Are You There God? It's Me, Margaret," Kelly Fremon Craig's celebrated movie adaptation of the landmark Judy Blume YA coming-of-age novel. Peyton Reed had nothing but good things to say about Fortson in the "Quantumania" audio commentary, admitting that it was "tricky" to recast Cassie because Fortson "is such a winning personality."

This is also why Reed felt it all the more important to have a completely different person play Cassie in "Quantumania," so as to emphasize how much the character had changed over the years:

"And […] now that you're with 18-year-old Cassie, you had to really like the idea, 'Oh, wow! She grew up into this person.' Cassie has ideas of her own now. She's an ideality and she has some different ideas than her dad about what it might take to be a hero and what justice means in the world."

There's a lot to criticize in "Quantumania," starting with the slapdash CGI (the result of Marvel vastly over-stretching its VFX artists). Then there's the way the threequel abandons what worked in the first two "Ant-Man" movies (the breezy vibe and Scott's colorful heist crew) in order to fulfill its corporate mandate as a key building block in the MCU's Multiverse Saga. Also, for a movie that's stuffed to the gills with psychedelic imagery and the zany residents of the Quantum Realm, it's strangely joyless. Kathryn Newton, however, emerges pretty blameless from the wreckage and does as good a job as anyone could as Cassie, given what she had to work with.

Still, let's pause a moment to pour one out for Emma Fuhrmann, the Cassie Lang who never really got a chance to earn her Ant-stripes.

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The post Why Ant-Man and The Wasp: Quantumania Brought in Kathryn Newton as Older Cassie Lang appeared first on /Film.