So what book is Musk into now? Bloomberg writer Tom Radall recently asked him: “Actually, I’m reading a book called Twelve Against the Gods, by [William] Bolitho,” Musk said. “It’s really quite good.”

His mere mention of the somewhat rare book—which features biographies of 12 historical figures, from Alexander the Great to Woodrow Wilson—sent readers scrambling to buy copies. Radall noted that the price of the book on Amazon.com shot up from a little more than $6 to $99.99 within hours before the stock of around a dozen copies sold out.

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Amazon’s page for the book, first published in 1929, now reads “Out of Print—Limited Availability.” The English-language version also appears to be sold out on AbeBooks, Alibris, and Barnes & Noble.

Musk’s fondness for Twelve Against the Gods is notable for a few reasons. The author (whose full name was William Bolitho Ryall) was a journalist and writer who was born in London but raised in South Africa, where Musk also spent his childhood. Meanwhile, the theme of the book is the adventure of bucking established practices in pursuit of greatness. Randall noted that each of the book’s subjects “fought against the conventions of their times, for better or for worse.”

It comes as little surprise that Musk might find some inspiration, or solace, in the lives of such figures, as he’s currently trying to upend multiple massive industries.

• Tesla is taking on the auto industry with its growing crop of electric cars, as well as its massive Gigafactory for manufacturing lithium-ion batteries.
• Musk’s privately held SpaceX is working with NASA to send an unmanned capsule to Mars within a couple of years.
• And recently, Musk has come under fire recently for perceived conflicts of interest in his quest to merge Tesla with SolarCity, the publicly traded solar panel installer run by his cousin, Lyndon Rive, and which counts Musk as its largest shareholder.

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Is it safe to assume that Elon Musk envisions himself as a potentially great and historical figure? He wouldn’t be far off base if he does, considering the massive scale of what he’s trying to achieve across various industries and platforms. (And, of course, he’s also been quick to chafe when anyone questions his practices.)

At the very least, it’s not hard to add Musk to Bolitho’s historical iconoclasts, which is what Bloomberg’s Randall very nearly does, ending his article with the line: “If Bolitho lived today, he might very well be busy researching a 13th chapter.”