Let’s play a game. Imagine Avatar. Imagine everything you liked about Avatar. Now remove all the 3D.

Now remove the breathtaking visuals. Now remove all the nuanced motion capture performances, the emotive score, the cutting-edge technology and the spectacle of seeing a perfectly-realised alien world come to life in such perfect detail that you secretly wished you live there. You’ve got a slightly gormless environmental story about a lanky blue Jesus who flies around on a pterodactyl having it off with tentacly aliens all the time.

Or you’ve got the Avatar prequel novel that James Cameron wants to write. It doesn’t matter which; they’re just as rubbish-sounding as each other.

There’s no doubt that Avatar was a cinematic game-changer. In the near future, we’re going to be bombarded by hundreds of films that’ll pinch elements from Avatar and claim it as their own. Maybe we’ll see more films embrace digital 3D. Or maybe we’ll see more films experiment with motion capture technology. Or maybe we’ll start to see less of a reliance on flesh and blood actors in the filmmaking process. Who knows?

But what we’re hoping, though – what we’re really hoping – is that Avatar influences other directors to the degree that, once they’ve made their film, they feel compelled to rush out and bang together a bloated, badly-formed, utterly superfluous 900-page novel about the world that they’ve created. Because that’s what James Cameron has decided to do with Avatar. Look, MTV says so and everything:

“Jim is going to write a novel himself,” the film’s producer, Jon Landau, told us. “Jim wants to write a novel that is a big, epic story that fills in a lot of things… it would go into much more depth about all the stories that we didn’t have time to deal with — like the schoolhouse and Sigourney [Weaver's character] teaching at the schoolhouse; Jake on Earth and his backstory and how he came here.”

Oh gee, why not throw in a scene where Colonel Quaritch catches Jake towelling down after a shower and they end up bumming each other in slow-motion to the sound of I Want To Know What Love Is while riding a rainbow-coloured unicorn? Because, you know, if James Cameron wants to have a go at writing some Avatar fan fiction, he may as well go the whole hog.

Seriously, James. Enough’s enough. You’ve already made a three-hour film about the world of Avatar. We don’t need a book to fill in the gaps on top of that. Learn to self-edit. Because you know who you’re starting to sound like? George Lucas. Once you start writing books and entertaining the possibility of sequels, you won’t be able to stop. You’ll start chucking out Avatar spin-offs and cartoons and holiday specials and weird disco-influenced musicals starring Donny and Marie Osmond with barely a hint of quality control.

And you know how this’ll end? With a terrible Avatar prequel that’ll largely revolve about trade negotiation and taxation banding within Pandora’s bureaucratic infrastructure, that’s how. Worse still, you might end up growing a beard and refusing to wear anything but plaid shirts until your neck disappears completely. Honestly James. Put down the pen while you still can.

Follow hecklerspray on Twitter