In 2009, Reif Larsen wowed the literary world with “The Selected Works of T.S. Spivet,” a postmodern road novel featuring a 12-year-old prodigy and festooned with maps, illustrations and marginalia. If young Spivet’s thoughts were a little too mature at times, young Larsen displayed an admirable willingness to think outside the traditional narrative box.

The promise shown in that first novel is more than fulfilled in the grandly ambitious “I Am Radar,” another masterpiece of geekhood.

It, too, has maps, illustrations, footnotes — even a bibliography — but if Larsen’s debut looked like a Donald Barthelme assemblage, this one resembles something by Thomas Pynchon. Like Pynchon’s novels (which are alluded to a few times in the text), “I Am Radar” is thick with scientific references, tech talk, arcane erudition and historical research. Set over the past 40 years, it yo-yos between New Jersey, Norway, Yugoslavia, Cambodia and the Congo.

The übergeeky title character, Radar Radmanovic — named after the chopper-detecting character in “M*A*S*H” — is a radio engineering prodigy but also a freak. Born black to white parents during a blackout in 1975, he baffles the scientific establishment, then undergoes a mysterious treatment in Norway that turns him white, though it leaves him nearly bald and subject to epileptic seizures. While in Norway, he and his parents learn of an “experimental puppet troupe” called the Kirkenesferda, which, since World War II, has been staging “happenings” that illustrate scientific ideas like neutrinos and superstring theory in war-torn regions. During another blackout, in 2010, 35-year-old Radar is invited by the troupe to put on a performance in the Congo, where he meets a strange bibliophile assembling a gigantic library in the jungle who likewise underwent a skin change from dark to light. The ending is nearly indescribable, a phantasmagorical display of apocalyptic magic realism.

In between the three chapters on Radar, there are two novella-length accounts of other whiz kids and their families in Yugoslavia and Cambodia, where the Kirk­enesferda eventually shows up to stage elaborate puppet shows in protest of the brutality of war.

“I Am Radar,” by Reif Larsen (Penguin)

In Larsen’s gifted hands, puppetry becomes a multilevel metaphor for the role of art in a violent world. “War happens when society forgets its artists,” one puppeteer says, meaning that art reveals the gut-level similarities between people, while wars are caused by those who violently insist on skin-deep ethnic, religious or ideological differences. Puppetry also is a metaphor for the way novelists operate. The Kirkenesferda’s activities are analogous to the elaborate show puppeteer Lar­sen is staging for us.

Then again, some of the Kirk­enesferda’s happenings go unobserved, and those end in disaster. They sound like the kind of over-conceptualized and theory-addled performance art that is more interesting to think about than to sit through, and the troupe has no effect on the political status quo. In a sense, “I Am Radar” is an avant-garde novel dramatizing the inconsequence of avant-garde art.

But Larsen’s brainy book is no ephemeral performance piece. He grapples with time-honored questions of free will, predestination, man vs. nature and the tensions between parents and children. But it’s the ingenuity with which he does so, rather than the themes themselves, that elicits admiration. Each of the foreign settings contains thick descriptions of its culture, history, folklore and literature and is laced with words and phrases in its native tongue. (In addition to Norwegian, Serbian, French and Cambodian, there are passages in sign language and Morse code, and even African talking-drum transcriptions.)

And since “I Am Radar” portrays several bibliophiles, there’s lots of discussion about books, along with some literary in-jokes: In the African chapter, set in 2010, we’re told of “one small feeder boat from South Africa, the Colonel Joll, which looked as if it had been here for some time,” referring to a character last seen in J.M. Coetzee’s 1980 novel “Waiting for the Barbarians.” The experimental theater troupe names a goat Bertolt Brecht. Radar crosses the ocean in the Aleph, the title of a book by Jorge Luis Borges, as important an influence on Larsen as Pynchon. It appears again in the novel’s bibliography, a clever mixture of real and fictitious works that gives further evidence of the network of literary allusions supporting this story’s wide-ranging concerns. An item in the bibliography also tells us how Radar’s story ends.

Fifteen years ago, critic James Wood used the term “hysterical realism” to deride novels like this one, those that feature wacky characters involved in cartoonishly convoluted plots about mysterious connections, and often spiked with pop references and nerdy erudition. But this genre includes some of the greatest novels of our time, from Pynchon’s “V.” to David Foster Wallace’s “Infinite Jest.” That’s the troupe Larsen has decided to join, and “I Am Radar” is a dazzling performance.

Steven Moore is a critic whose latest book is “William Gaddis: Expanded Edition.”

I AM RADAR

By Reif Larsen

Penguin Press. 656 pp. $29.95