Doreen Green—The Unbeatable Squirrel Girl—has defeated the likes of Doctor Doom, Galactus, M.O.D.O.K, and Thanos in recent years. They don’t call her “unbeatable” for nothin’, folks.

On September 13, witness the next chapter in her invincible story as writer Ryan North and artist Erica Henderson present UNBEATABLE SQUIRREL GIRL #24! Seen previously frolicking in a nature preserve full of dinosaurs, Doreen gets a big surprise when one of those prehistoric beasts turns out to be Ultron in the form of a Tyrannosaurus rex!

It seems a rumble for the ages awaits in the cards—so, what can we learn about this Jurassic joust before issue #24 hits shelves? Series writer Ryan North probably knows—let’s ask him!

Marvel.com: Squirrel Girl has single-handedly defeated some of the most powerful beings in the universe…but will this newest foe end her winning streak at last?

Ryan North: Obviously you’ll have to read the comic to find out—but we did put “unbeatable” on the cover, so I wouldn’t be dressing up neighborhood squirrels in black funereal garb just yet. But how? How could she do it? Ultron has incredible powers and has previously defeated the Avengers as a group—and she’s alone in the dangerous landscape of the Savage Land.

Seriously, please let me know how she could do it. I have written myself into a corner and need ideas stat.

Marvel.com: What’s it like writing a character that’s so powerful—and so funny?

Ryan North: With Doreen I see this really clever, competent woman who gets underestimated by people who don’t know her—and there’s a lot there that most of us can relate to. In a sense, it’s so easy to write Squirrel Girl because she’s so well-defined; she’s a ridiculously powerful person (she has all the powers of squirrel and girl, after all) and she’s also really empathetic. She’d rather discuss a dispute before heading right into a fist fight. In real life, I try to do the same, and I, too, have had many more discussions than I have fist fights—so in that sense she can be inspired by reality as well.

She also has this slightly skewed view on the Marvel Universe—it’s the point of view of a computer science student (Doreen!) and her friends (Nancy! Tippy-Toe! Brain Drain! And more!) who see everything with fresh eyes.

Marvel.com: What do you think makes Squirrel Girl so unbeatable?

Ryan North: She’s smart, she’s kind, and she knows computer science. Also: squirrels. A literally unbeatable combination—it’s so powerful that I’m surprised it hasn’t shown up in fiction until now!

Marvel.com: What’s your favorite element of this storyline?

Ryan North: Ultron is lots of fun, and turning him into a gigantic Tyrannosaurus rex only makes him even more fun. I am always happy to write a dinosaur, and I hope that my previous Dinosaur Comics work has given me that expertise in writing giant Tyrannosaurs.

I think it’s impossible not to have fun when you’re putting your characters in some sort of “Jurassic” kind of “park”—especially when they’re facing down a killer robot dinosaur named Ultron. There is literally nothing not to love in that sentence.

Marvel.com: So, how did Ultron turn into a dinosaur!?

Ryan North: Well, I don’t want to give it all away (we reveal it in the next issue!) but Ultron always rebuilds himself—even if only a little bit of him survives. In the past, we’ve always assumed that only one part rebuilds, so only one Ultron exists at a time, but if that wasn’t the case…and if that extra part dropped into the Savage Land…

Marvel.com: What makes the Savage Land the perfect setting for this story?

Ryan North: I love the Savage Land because it’s there, in the present day, just, you know, hanging out in Antarctica. Like, everyone in the Marvel Universe just goes about their business, paying their bills and taxes, and never once stops and says, “Hey, wait a minute, there are alive dinosaurs on Earth right now,” and hops on a plane to go see them. It was fun to play up Nancy’s disbelieving reaction to that at the start of the arc, because I had the same reaction when finding out about the Savage Land way back when. It’s a big deal and I think super heroes and regular people should be visiting it way more often!

Marvel.com: Definitely! What will your interpretation of the Savage Land be like?

Ryan North: We really wanted to do the dinosaurs justice. The Savage Land first showed up in Marvel Comics decades ago—but our understanding of dinosaurs has evolved since then. Erica Henderson, the series artist, insisted (she sent me several emails even after I agreed, just to make sure I didn’t forget) that we explain why the Savage Land dinosaurs didn’t have feathers—since we now understand that most dinosaurs did. The explanation in the book (that the Savage Land inhabitants did have feathers but lost them over the 65 million extra years they had to evolve in Antarctica) solved a scientific problem in the Marvel Universe that had bugged Erica for years. We’re always happy to make these stories about super powered people more scientifically accurate!

Plus, if you keep your eyes peeled, you’ll see some of my favorite species of dinosaurs in the Savage Lands. I think this is the best arc we’ve done yet—and I’m really excited that we’ll soon be able to share it all with you!

UNBEATABLE SQUIRREL GIRL #24, by Ryan North and artist Erica Henderson, launches on September 13!