There’s a good deal of “Se7en” in “A Walk Among the Tombstones,” Scott Frank’s sophomore feature. Unlike 2007’s “The Lookout,” which he directed from his own script, however, this one is an adaptation based on Lawrence Block’s 1992 novel, part of his series about PI Matt Scudder, an alcoholic ex-NYPD cop. (Hal Ashby’s 1986 “8 Million Ways to Die” was the only previous attempt to transfer the character to the screen.) It doesn’t match the quality of David Fincher’s film—it’s maybe 5 rather than 7, though it references the 12 steps of the AA program as a major plot point —but it’s a moodily effective piece of period pulp that moves slowly but delivers some genuinely creepy moments while also making a few serious missteps.

It also gives Liam Neeson the opportunity to add some real shading to a part that in many respects resembles a far less gung-ho version his “Taken” character. In Frank’s updated version (the year is now 1999), Scudder is a world-weary sort who quit the force some years earlier because he’d been in a street shootout that, as we eventually learn, ended badly. He’s also a technophobe, in the months immediately preceding the Y2K scare of January 1, 2000, refusing to use cell phones and computers. And he regularly attends AA meetings.

It’s there that he meets Peter Kristo (Boyd Holbrook), a junkie who asks him to meet with his brother Kenny (Dan Stevens), a well-to-do yuppie drug dealer. Kenny informs Matt that his wife has been kidnapped and gruesomely killed, despite the fact that he paid the demanded ransom. He asks Scudder to track down the killers, and after an initial refusal, the PI changes his mind. He works on dogged investigation and, as he tells TJ (Brian “Astro” Bradley), a smarty-pants homeless kid who helps him do some research at the library and then inveigles his way into becoming Matt’s virtual assistant, on instinct and dumb luck. All those are certainly involved in his discovery that the murder of Kristo’s wife is part of a pattern that included the murder of several other women, all of them somehow related to the drug trade. It also leads him to Loogan (Olafur Darri Olafsson), a cemetery groundskeeper who was one of the three men involved in the abductions, but the identities of the other two remain unknown.

To Scudder, that is, but not to us, because Frank chooses to tell the audience who the perpetrators are fairly early on: a couple of guys, apparently gay, who apparently have had some connection with the DEA and just enjoy brutalizing and mutilating women, though the ransom money they get isn’t entirely unwelcome. Ray (David Harbour) and Adam (Albert David Thompson) are initially shown only at a distance as shadowy presences, but soon we see them in their kitchen, sharing breakfast and chatting in a desultory fashion. One could argue that they’re disclosed too early for the film’s good, but the real problem is that they’re never fleshed out as characters. Ray’s the insolent, taunting voice on the phone and Adam’s the laconic fellow with the beady eyes and the wide array of cutting tools, and that’s about it. Neither, frankly, is an interesting as Loogan, about whom Olafsson conveys more in his moments on screen than either Harbour or Thompson manages to do in potentially juicier parts.

Scudder, however, is able to force them to reveal themselves when they kidnap the daughter of another drug lord, Yuri Landau (Sebastian Roche), and he, Kenny and Peter plan to bring them down when they attempt to claim the ransom money. It all leads to a tense final reel, with a showdown—a series of showdowns, actually—all decked out in blood and gore. The gloomy tone persists to the very end, even if Scudder and TJ wind up pals. And one can be grateful for that: when Frank and cinematographer Mihai Malaimare, Jr., go outside their visually dank comfort zone—in a slow-mo sequence in which the killers observe their next victim, Landau’s pretty daughter Lucia (Danielle Rose Russell), crossing the street walking her dog, it’s as though a clip from a Brian De Palma picture had suddenly been plopped onto the screen in error, and the effect is creepy in all the wrong ways.

The fact of the matter is that “A Walk Among the Tombstones” isn’t all that clever in terms of plot, and its undercurrents of misogyny and homophobia are disconcerting. Its 1999 setting, moreover, invites heavy-handedness in period detail, and Frank and production designer David Brisbin don’t entirely resist giving in to it.

But the film does cast an atmospheric spell, Neeson brings surprising conviction to his role, Stevens—in a far cry from his current turn in “The Guest”—is convincing as a man coolly determined to take vengeance, and Holbrook offers a loose, skillful turn as a hopeless addict. Even Bradley, despite a less than credible character to play, comes across as likable.

Frank sometimes stumbles along the way, but you could do worse than join his “Walk.”