One of the better supernatural thrillers I saw a few years back was The Ninth Gate, a rather understated film about a mercenary rare-book dealer (Johnny Depp) hired by a collector (Frank Langella) to investigate what he believes to be a forged copy of a mysterious book rumored to have the power to summon the Devil himself.

Only recently, I discovered that the movie is actually based on a novel, originally written in Spanish by Arturo Pérez-Reverte, entitled The Club Dumas.

While I do recommend the film, I’ve always thought it suffered from the bane of all but a select few supernatural thrillers: the lame-ass ending. The novel, on the other hand, I recommend without reservation. It turns out that about half the plot was simply dropped from the film (understandably so, but much better to have it in) and the ending is much more satisfying.

The book is more literary, complicated, and intellectual. Not surprising, given the different media, but the story benefits from the added twists and turns, and sly textual self-awareness. It’s one of those stories about stories that’s lessened when that element is removed, as it is in the film.

So rent the movie – really, it’s good! – but do yourself a favor, and read the book first.