What are you thinking?

That’s the thought that ran through my mind when I read the Hollywood Reporter yesterday and learned that Randall Wallace had taken on “The Arcanum,” a film adaptation of the book of the same name.

In its written form, “The Arcanum” is a historical fantasy novel set in 1919 that follows Sir Arthur Conan Doyle as he leads his cadre of similarly famous figures — Marie Laveau, Harry Houdini, and H.P. Lovecraft — in an attempt to save the world from a madman bent on destroying it. It’s a first-time novel that was absolutely blasted by Publishers Weekly, which recommended readers skip it and read Tim Powers and Alexander C. Irvine instead.

And then there’s that striking similarity to another film already out there: The League of Extraordinary Gentlemen. Yeah, bringing together historical heroes in an action movie is a neat idea. Once. I liked “League” just fine, but I certainly wouldn’t wish a sequel on anyone. And I certainly wouldn’t risk producing such a similar film based on a book with such bad reviews. I mean, come on: “Arcanum” has more red flags than the Chinese army!

Now, I’ve been reminded lately how wrong I was when I predicted the miserable failure of “300.” In spite of encouraging the entire world to go around shouting, “This! Is! Sparta!” in public places, that film turned out to be mostly perfect for what it was delivering. So maybe Wallace sees something we don’t — maybe “Arcanum” has potential that couldn’t be realized in novel form.

We’ll have plenty of time to muse on this. The project isn’t even cast yet.