In "Untraceable," the ever-capable Diane Lane plays an intrepid agent in the FBI's cyber-crime unit who is on the virtual trail of a psychopath who broadcasts his grisly torture killings on the Web.

Although the plot might feel as if it's made up of borrowed bits and bytes, thanks to Lane's typically committed performance and Gregory Hoblit's usual intelligent, brisk direction ("Fracture," "Primal Fear"), the picture remains sufficiently compelling.

Toss in a killer who is sick and twisted enough to satisfy the "Saw" set, and you've got yourself a marketable Screen Gems release that should download solid midrange numbers.

Lane's Special Agent Jennifer Marsh is a single mother by day who works nights in the FBI's Portland, Ore., bureau trolling the Internet for fast-moving sexual predators and identity thieves.

It's a particularly intense game of cat and mouse that requires lightning-quick decisions and even quicker fingers on the keyboard, but Marsh and her partner, Griffin Dowd (Colin Hanks), usually nail the perps.

Trickier is finding a way to extricate herself from her high-tech, wired existence.

Driving home from work, she presses the OnStar button in her car to find out just how bad the traffic tie-up is in front of her, but she'll soon discover the annoying rubber-neckers checking out an accident is nothing compared to the growing millions logging onto a disturbing Web site offering real-time killings.

The first victim is a kitten, but the ante is upped considerably on killwithme.com, showing the systematic torture of kidnapped human prey whose ultimate time of death is hastened by the numbers of visitors to the site.

Initially the victims appear to be randomly snatched, but it soon becomes apparent that the killer is actually closing in on Marsh and her loved ones.

Hoblit, whose father was an FBI agent, maintains an effectively tense pace while making unpleasant observations about society's voyeuristic impulses, but it still can't cover one glaring character implausibility in the script -- credited to Robert Fyvolent and Mark R. Brinker along with Allison Burnett -- that lands Marsh in major hot water.

That misstep aside, "Untraceable" is highly watchable, anchored sturdily by Lane's convincing performance.

In addition to displaying an impressive dexterity with all that technical jargon, she really gets under her character's skin, struggling to establish some kind of division between work and home.

She gets solid support from Hanks, who shares his dad's easy affability and vocal quality, along with Billy Burke as a Portland police detective who joins forces with her, and reliable Mary Beth Hurt as her supportive mother.

Tech specs are all high res, with cinematographer Anastas Michos giving those unpleasant visuals a fittingly chilly, clinical appearance; while editor David Rosenbloom, a frequent Hoblit collaborator, cuts effectively to the bone.

Screen Gems
A Lakeshore Entertainment production in association with Cohen/Pearl Prods.
Director: Gregory Hoblit
Screenwriters: Robert Fyvolent & Mark R. Brinker and Allison Burnett
Story: Robert Fyvolent & Mark R. Brinker
Producers: Steven Pearl, Andy Cohen, Tom Rosenberg, Gary Lucchesi, Hawk Koch
Executive producers: Richard Wright, Eric Reid, James McQuaide, Harley Tannebaum
Director of photography: Anastas Michos
Production designer: Paul Eads
Music: Christopher Young
Costume designer: Elisabetta Beraldo
Editor: David Rosenbloom
Jennifer Marsh: Diane Lane
Detective Eric Box: Billy Burke
Griffin Dowd: Colin Hanks
Owen: Joseph Cross
Stella: Mary Beth Hurt
Running time -- 100 minutes
MPAA rating: R