"The Signal" is an inspired low-budget horror item with a rough and tumble guerilla filmmaking flair. What it lacks is a steady focal point to rattle the viewer's interest and emotions for an hour and a half. As it stands, the picture shifts so radically in tone throughout that it's tough to get as immersed in its apocalyptic scenario as one should. Are directors David Bruckner, Jacob Gentry and Dan Bush out to make a scary movie or a lighthearted romp that happens to have gore?

Unhappily married Mya (Anessa Ramsey) is in love with the earnest and romantic Ben (Justin Welborn), but not sure if she has the courage to leave gruff husband Lewis (AJ Bowen). Shuffling home late to her apartment while she ponders her next move, Mya senses something is off-kilter almost the moment she steps into the building. Dwellers are arguing with each other in the hallways, screams are faintly heard through the walls, and it isn't long before Lewis himself is bashing his friend's skull in with a baseball bat. Mya narrowly escapes and, the next morning, walks outdoors into a living nightmare of corpses and raving madmen. The source of the sudden chaos seems to be a mysterious signal emanating from televisions, radios and telephones. With all electronic communication systems shut down, the few people who have avoided literally losing their minds are now on their own to survive.

"The Signal" has a unique backstory. Cut into three parts (labeled "Transmissions") that run approximately thirty minutes each, directors David Bruckner, Jacob Gentry and Dan Bush helm their own respective section and apparently were given free reign as long as it narratively tied into the other two segments. The opening third, directed by Bruckner, is easily the best, drawing the audience immediately into the plight of Mya as she comes to terms with two men who love her and only one whom she loves back. Her moral conscience over cheating on Ben is shoved into the background as she is placed within a nightmarish circumstance, and the film bubbles over with increasing paranoia and fear. One part "28 Days Later" and one part "Mulberry Street," the picture was on track to truly impress as a taut, serious and gritty genre effort that featured one of the more sympathetic screen heroines in recent memory.

As the second section, directed by Gentry, gets underway, "The Signal" starts to sputter as the point-of-view alternates from Mya to a passerby on the street, friendly complex landlord Clark (Scott Poythress). When both he and down-on-her-luck New Year's Eve party host Anna (Cheri Christian) are forced to separately kill in self-defense, they hole up in her home and try to make heads or tails out of the situation. Meanwhile, more than one guest pays a visit, and the results aren't exactly festive. The middle half-hour of "The Signal" plays like someone has seen 2004's "Shaun of the Dead" too many times, and, although there are a few droll one-liners and amusing elements—Cheri Christian is a stitch as the cheerfully put-upon Anna—the comedy severely detracts from the unsparing mood that had previously been created.

By the time the final part, directed by Bush, comes around and makes an attempt to return to a more dramatic tone (albeit one that is now also outlandish in an old-school Cronenberg kind of way), the viewer has been jerked around so much that the proceedings are more confusing than frightening. The film's internal logic is thrown out the window, established rules are broken or contradicted to satisfy the needs of the story, and plot holes get out of hand. Why, for example, does the signal transmission turn some people into total psychos, while others proceed to function with reason and can be pulled out of their trance with the virtual snap of a finger? And how do certain characters' level of injuries keep changing? The inconsistencies run rampant.

"The Signal" ends on a final shot so simple and yet so pure and powerful that it nearly makes up for the wrongs of the last hour. This conclusion, along with newcomer Anessa Ramsey's potentially star-making standout performance as Mya and the haunting use throughout of Joy Division's song "Atmosphere" covered by Ola Podrida, are so good that it's a shame the rest of it is uneven and sort of meandering. "The Signal" is technically well-made and may even have a slim chance at gaining a minor cult following. Alas, its flaws of the pitch and screenwriting variety are too overwhelming to ignore, especially when greatness was initially only an earshot away.