Gee, doesn't that make you want to dive right in? Well, sure, the style's a little tricky, but we think there's a reason. Let's check it out:
"The Purloined Letter" is styled more like a play than a story—it's almost entirely dialogue. The main person doing the talking is Dupin. Actually, the narrator is doing all the talking, but he's telling us what Dupin is saying. And Dupin, like many Poe characters is fond of complex sentence structures, like here:
The principle of the vis inertiœ, for example, seems to be identical in physics and metaphysics. It is not more true in the former that a large body is with more difficulty set in motion than a smaller one, and that its subsequent momentum is commensurate with this difficulty, than it is, in the latter, that intellects of the vaster capacity, while more forcible, more constant, and more eventful in their movements than those of inferior grade, are yet the less readily moved, and more embarrassed and full of hesitation in the first few steps of their progress. (107)
Anyone else hear crickets?
Here Dupin is discussing the scientific principle of inertia, which basically states that things like to be still (or inert) and that big things (like rocks) really like to be still. In other words, it's easier for a small body to get moving—but also stop—than it is for a large body. (If you've ever, say, pushed a piano down a hill, you'll know what we mean.) Similarly, Dupin says, a person with a big brain will have more trouble getting started on something than a person with a small brain.
Whether you believe this or not, you can see our point: Poe isn't making it easy for us.
Even when he's not going on about physics, the style call be wordy and difficult. Take this little nugget: "he forbore to enkindle the wick" (3). Translation: He didn't light the candle. Why didn't Poe just say that? Well, for one, writing styles were just different in the nineteenth century. But even for the nineteenth century, that's a pretty distinctive way of saying "he didn't light the candle."
But here's the thing: it's also more precise that saying "he didn't light the candle." "Forbore" is often used to imply that you restrained yourself from doing something you wanted to do or were about to so. So to say that he "forbore to enkindle the wick" really means something like the even wordier, "He was about to light the candle and then changed his mind and stopped himself." (We can't help you with "enkindle the wick.)
The point is, this is a precise and analytic style. The narrator apparently always says exactly what he means—this is one of the reasons we know to trust him. And it's probably his own way of participating in the process of discovery. G— describes his process of analyzing where the letter might be. Dupin analyzes G—'s process of analyzing, and then describes his own process of analyzing. And then the narrator provides a final later of analysis through his precise, if diffiuclt, style.
In fact, these layers of analysis become another kind game, one that the style invites us to play along with. Because there is so much to analyze in this relatively brief story, the game can go on for as long as we're willing to play.