The contagion started four years ago, when Brallier, a 2005 graduate of IC’s cinema and photography program, released the first book in The Last Kids on Earth series. The apocalypse-set story, featuring zombies and giant monsters, is written for an elementary and middle school audience. The series, which has now spent 25 weeks on The New York Times bestseller list, has its own animated Netflix special and a forthcoming series, created by Atomic Cartoons and voiced by stars like Rosario Dawson, Bruce Campbell, Mark Hamill, and Catherine O’Hara. The sixth installment in the book series will come out in April.

“It’s been incredible to watch the series grow—and I’m just incredibly grateful to Viking Children’s, Netflix, Atomic Cartoons, and everyone else who’s been involved,” said Brallier, who acts as creator, writer, and producer for the show. “To see this book series that started as a little spark of an idea in my head one afternoon grow to something so much bigger is just, I dunno, strange, cool, exciting? There’s not quite one word to describe it.”

The books center around 13-year-old Jack Sullivan, an Oreo-eating, Mountain Dew drinking, unlikely hero who lives in his tree house and joins forces with his classmates to fight zombies and Godzilla-sized monsters. Fast Company described it as The Walking Dead meets The Goonies.

Next on the horizon for The Last Kids? A line of toys and action figures. “It’s beyond my wildest dreams,” Brallier told Fast Company. “If you told me in 2015 when I was delivering the first manuscript that the idea I had for a Little League baseball bat that becomes a sword would be an electronic toy that lights up and glows, and is going to be available in the stores for people to buy, my brain would’ve melted.”