Big Brother is watching and this is GPS like you’ve never seen. Forget about honing in on a car’s license plate from a satellite. In this not-too-distant-future, the Feds can virtually see exactly what you did four days in the past. But let’s not get ahead of ourselves (pun intended).

The film begins with a ferry full of Mardi Gras partygoers on Lake Pontchatrain in New Orleans. We watch as happy families with children and uniformed Navy sailors board the vessel on a festive Fat Tuesday afternoon. On the car deck of the boat is an SUV outfitted with a bomb. As a guard checks the vehicles, an explosion blasts the ferry apart. Newscasts report over 500 people dead.

ATF agent Doug Carlin (Denzel Washington, "Inside Man" and Oscar winner for "Training Day") is sent to investigate. He’s all over the crime scene, including the pilings and girders of a bridge overlooking the water, which is where FBI agent Pryzwarra (Val Kilmer, "Kiss Kiss, Bang Bang," "Alexander") finds him. Carlin (emphasis on the "lin," he corrects) determines that the person responsible detonated the bomb from the bridge. The two agents carry on informative and professional banter and it’s evident that they respect each other. Pryzwarra invites Carlin to sit in on a demonstration of groundbreaking technology, and enlists the ATF agent’s help to figure out what to look for. The secret weapon is a time machine, of sorts.

The device can follow an individual’s movements at any moment, four days ago. Pictures appear on a TV-like monitor. Two computer impresarios (played by Adam Goldberg and Ericka Alexander), adept at manipulating time and space, get a fix on the face of the bomber. But he cannot be identified yet.

One body that washes up on shore is a puzzler. At first the woman looks like a victim of the ferry disaster, except that her time of death is prior to the bombing. She is identified as Claire Kuchever (Paula Patton of "Idlewild"), and her vehicle is somehow tied to the perpetrator. Carlin is convinced that her actions during the days leading up to the attack can lead the government to the terrorist.

Carlin’s other hunch is that the dead woman is familiar to him. He’s seen that face before. When the "miracle cameras" pull up Claire in her apartment four days prior, Carlin has that feeling that he’s seen this. Claire can be observed from any angle and can be tracked through the walls as she moves about her space. She’s on the phone with the killer, who wants to buy an SUV that she has for sale. Through the magic of the camera (still photographing the past), we discover that his name is Oerstadt (James Caviezel, Jesus in "The Passion of the Christ").

When Carlin visits Claire’s home he finds bloody clothing and an overwhelming feeling of déjà vu. We’ve all had that prickle of recognition of a scene that we find ourselves in the middle of and know that we’ve been here before, and what’s going to happen next. Then…it’s gone.

The most interesting hypothesis put forth here is that the continuum of this déjà vu experience may be two-way. When Carlin introduces a beam of light from the present/future into the space of the past/present, where Claire talks with a child, there is a spark of recognition. Don’t fight it, just go along for the ride.

What happens next in this story, we’ll leave for you to discover. Denzel Washington is a cool character here, observant and quick with the deductions. Director Tony Scott (reunited here with Denzel from "Man on Fire") presents a credible take on a flawed script by Bill Marsilii and Terry Rossio, who get lost in a one-eyed, past meets present car chase. You’ll know the scene when you see it. "Déjà Vu" illustrates the point that a fine actor¾ that’s Denzel Washington¾ can elevate a film tremendously.