a walk among the tombstones trailerThe trailer for "A Walk Among the Tombstones" is further proof that Liam Neeson isn't afraid to tap into his dark side.

Opening September 19, "A Walk Among the Tombstones," based on the 1992 Lawrence Block novel of the same name, sets unlicensed private investigator Matt Scudder (Neeson in this movie, Jeff Bridges in 1986's "8 Million Ways to Die") on a mission to find the men who murdered the wife of a not-so-nice guy. As often happens in these kinds of books/movies, all is not what it seems.

Here's the full summary from Universal:

Based on Lawrence Block's bestselling series of mystery novels, A Walk among the Tombstones stars Liam Neeson as Matt Scudder, an ex-NYPD cop who now works as an unlicensed private investigator operating just outside the law. When Scudder reluctantly agrees to help a heroin trafficker (Dan Stevens) hunt down the men who kidnapped and then brutally murdered his wife, the PI learns that this is not the first time these men have committed this sort of twisted crime...nor will it be the last. Blurring the lines between right and wrong, Scudder races to track the deviants through the backstreets of New York City before they kill again. Written and directed by Scott Frank (The Lookout), A Walk among the Tombstones is produced by Jersey Films' Danny DeVito, Double Feature Films' Michael Shamberg and Stacey Sher, Exclusive Media's Tobin Armbrust and Cross Creek Pictures' Brian Oliver. Universal will distribute the film in North America.