It’s 1933 and the world is facing imminent doom.

Luckily, Earth is in the capable hands of a reporter, her geeky research assistant and an enigmatic librarian from Arizona. Together, the unorthodox trio travel to Robot Planet, where they take down Earth’s sludge-monster alien foes, the Zygonians.

And that’s only Book 1 of “The Intergalactic Nemesis.” We haven’t even gotten to the robots and Soviet spies yet.

Part radio play, part graphic novel, “Intergalactic” brings its two segments — “Book One: Target Earth” and “Book Two: Robot Planet Rising” — to Spoleto Festival USA after a quick run off-Broadway and an appearance on Conan O’Brien’s talk show.

“I bet there isn’t a single other show in Spoleto this year that has been on Conan,” said “Intergalactic” writer/director/costar Jason Neulander.

The multimedia shows, both set in the 1930s, are Neulander’s ode to the rise of the comic book and a nostalgic tip of his hat to the heyday of radio drama.

“It uses two media that were invented in the 1930s to tell the story: comic books and radio plays,” he said. “What was fun about making the translation from radio to comic book, for me, was figuring out how to retell the story visually.”

“Intergalactic” got its start at Neulander’s small company, the Vanguard Salvage Theater, in Austin, Texas. At first, it was simply a radio play — Orson Welles’s “War of the Worlds” was the inspiration — complete with actors, piano accompaniment and an onstage Foley (sound effects) artist. According to Neulander, the show casually began to pick up steam with the theater-going crowd in Austin.

He was then asked to bring his show to a 2,400-seat theater in Austin. Realizing that the venue was too big for his intimate play, he had what he called a “life-saver moment” and decided to include actual comic art on a two-story-high screen during the show.

“It’s totally spectacular,” Neulander said. “Everything that’s visual in the show, in terms of the storytelling, is on-screen. It’s really hard to do a fight in radio, because there’s no dialogue in a fight, necessarily. Whereas in comic books, a fight is the perfect thing to portray because words are really secondary.”

With more than 1,200 images, “Intergalactic” proudly totes its “live-action graphic novel” badge, which is a long time coming for any comic book fan.

Up until 1978, comic books were considered a crude, immature art form, meant for teenage boys who were borderline delinquents. Looking for a way to market one of his short story cycles, Will Eisner coined the term “graphic novel.” Suddenly, this new art form, which also became known as sequential literature, was the comic book 2.0.

“The rise of the graphic novel is what happened when a new generation of readers came along and started taking comics seriously,” said Lee Konstantinou, associate professor of English at the University of Maryland. “A new generation of creators came along and saw in the form a lot of possibilities and a lot of potential.”

In 1986, the new medium had a major success with the arrival of two major limited-run series of comic books, “Watchmen” and “The Dark Knight Returns.” Readers were introduced to modern-day issues through brooding antiheroes, and both series would later be anthologized in book format.

However, Konstantinou said the book that put the graphic novel on the literary map was Art Spiegelman’s “Maus.” The Pulitzer Prize-winning 1991 novel documented the history of the Holocaust by using animal illustrations, with Jews depicted as mice and Nazis as cats.

“ ‘Maus’ is truly important to the history of the graphic novel,” Konstantinou said. “It’s now widely regarded as a masterpiece. It was this realization that you could tackle serious matter in comics.”

Which is not to say that comic books, graphic novels or whatever you want to call them have to tackle serious subject matter. After all, somebody needs to vanquish those sludgy Zygonians, with or without the help of Soviet spies.

Josh Austin is a Goldring Arts Journalist from Syracuse University.