"The Signal" is free for those who bought "Alan Wake" new. If you bought the game used, it'll cost you $7.

As you play through “The Signal,” the first downloadable add-on for Xbox 360 exclusive “Alan Wake,” it’s hard to imagine a game better suited to having its story continued in short episodes, released every few months, rather than in a proper sequel. The retail disc [review] already divvied the action up into six chapters; each episode after the first begins with a tidy little recap of relevant plot points from previous episodes.

And that’s exactly how “The Signal” began. (This is where I warn you that I’m about to dive into spoiler territory for anyone who hasn’t finished the main game. So stop reading here if you plan to play “Alan Wake” but haven’t gotten to it yet.)

When we last left the title character, he had rescued his wife, Alice, from the Dark Presence that resides in and around the logging town of Bright Falls, Wash. But Alan saved Alice at terrible cost to himself. The writer ended the game trapped in a cabin at the bottom of a lake, a hostage to the Dark Presence. Meanwhile, an alternate Alan, dubbed Mr. Scratch, may be running around Bright Falls, standing in for the real deal just as Bob did for Agent Dale Cooper in the series finale of “Twin Peaks.”

We won’t get to find out what happened to Alice, Mr. Scratch or the rest of the gang until at least the next episode. “The Signal,” which is free for anyone who bought “Alan Wake” new, concerns itself with Alan’s psychological battles against the Dark Presence. The episode focuses primarily on the efforts of poet Thomas Zane to reach out to Alan via a cell phone you find in the episode’s first scene.

The player spends the bulk of the chapter helping Alan seek out a place where the signal is strong enough to contact Zane in person. (In maybe the strangest use of in-game advertising ever, it’s pretty clear Verizon paid to put its logo all over a phone that gets such crappy reception that Alan has to wander around for two hours trying to fix the problem. Then again, it does work underwater. Hmm.)

While Alan hunts for a hotspot, “The Signal” fleshes out a gameplay element introduced in the final chapter of the main game: floating words that, when illuminated, come to life. For example, Alan may see the word “flare” floating in the air. If he shines his flashlight on the word and burns away the darkness, a flare takes the place of the word, and Alan can use it to keep at bay people possessed by the Dark Presence. “The Signal,” however, doesn’t just use this new trick for power-ups. It’s possible to clear some parts of the game without ever firing a single shot.

These words are often part of fantastic set pieces, such as an area that’s filled with so many words — both menacing and helpful — that it’s impossible to traverse without illuminating some of them. This turns the whole scene into a calculated, surgical bit of flashlight pointing, punctuated by gunfire.

In between the set pieces, the game offers up a twisted take on a Bright Falls as seen through the prism of the Dark Presence. Light poles twist up through the ground and, early on, Alan revisits several areas for the first game that have been corrupted for reasons that become clear as the story progresses.

One of the biggest problems in the first six chapters was that they tasked players with way too much collecting of items for a game that was supposed to be suspenseful and scary. In addition to manuscript pages, which advanced the plot and performed the essential role of contextualizing the game’s events, Alan was tasked with finding more than 100 coffee Thermoses. Why? It was never clear. In any case, the Thermoses are gone for “The Signal,” replaced by less frequent alarm clocks and often-amusing cardboard standees.

Given the end of the main game, it didn’t make much sense for Alan to continue to find manuscript pages, so those have been replaced with video you see on various TVs you come across. Though the presentation is different from the manuscript pages, the result is the same. “Alan Wake” is a game that scares you by telling you what’s about to happen to you, then surprising you with its unexpected execution. (There’s a great example of this fairly early on that I don’t want to spoil. Savvy players will know it when they see it.)

Even though it may seem like the entirety of “The Signal’s” plot can be boiled down into “Writer gets phone, searches for stronger signal and establishes contact with someone who wants to help him,” it’s a journey well worth taking. The gameplay is probably sharper than what you’ll find in previous chapters, and it’s obvious that “Alan Wake” is a story with plenty of interesting new tales to tell.