One of the most treasured capabilities of cinema—a power too seldom achieved—is to so thoroughly engulf audiences that they are made to believe the unthinkable. An even better film is one able to seemingly plant the viewer in the bodies of the characters onscreen, enmeshed in their lives and the circumstances that have led them to the position they are in. The rabidly anticipated "Cloverfield" pulls off both of these remarkable feats. After six months of growing hype, begun with the release in July 2007 of a frightening, purposefully obscure, title-free teaser trailer, there was the initial sense prior to the screening that the picture wouldn't possibly be able to live up to the impossible standards set by a complex and stunningly imaginative viral marketing campaign. Those fears, however, are snuffed out in the hauntingly tranquil, early-morning opening scene—a quiet respite to the almost unimaginable horrors about to take place.

Director Matt Reeves (1996's "The Pallbearer"), screenwriter Drew Goddard (TV's "Buffy the Vampire Slayer") and producer J.J. Abrams (TV's "Lost") deserve all the accolades that will be heaped upon them for bringing "Cloverfield" to such stark, nightmarish light. In the way that the story is told solely from the lens of a spectator's video camera, the film could have felt derivative of 1999's "The Blair Witch Project," a groundbreaking motion picture of its time, but does not. The naturalistic approach, aided by unaffected performances and the kind of overlapping dialogue and chaos that come from a person's home movies, works brilliantly for what, in essence, is a grand-scale monster movie spun out of a single person's small-scale point-of-view. There has never been anything quite like it—a breathlessly horrifying sci-fi/horror/disaster film that narrows its gaze not on the giant otherworldly attacker and the destruction left in its wake, but on the vulnerable human souls who, faced against insurmountable odds, find a strength and compassion inside of themselves that they could have never guessed they were endowed with.

The premise, as it were, is whittled down to the bare essentials and then goes about surpassing the viewer's expectations with the level of artistry, innovation and intimacy brought to the material. On an introductory title card, it is established that the following recording was recovered from incident site 'U.S. 447' ('area formerly known as Central Park'). What begins as a farewell tape commemorating a going-away party for Rob Hawkins (Michael Stahl-David), about to leave for Japan on business, turns into something entirely different when an enormous creature emerges from the New York City harbor. As Rob, brother Jason (Mike Vogel), Jason's girlfriend Lily (Jessica Lucas), and Lily's friend Marlena (Lizzy Caplan) attempt to survive amidst a catastrophic event unlike anything the world has seen before, appointed videographer Hud (T.J. Miller) clings to the camera, saying, "People are gonna want to see how it all went down."

Born from an idea producer J.J. Abrams got while visiting Japan with his son and realizing that America never really had an iconic monster movie to call their own like that country's Godzilla, "Cloverfield" is just about as authentic and large in scale as the genre has seen. That the film was made for a reported $25-million is frankly amazing and proves that a budget of hundreds of millions is unnecessary. The visual effects in bringing the monster(s) and the disaster itself to life are close to seamless; for an hour and a half, the viewer is led to wholly buy into the idea that Manhattan has become an apocalyptic landscape. Images recalling those seen on 9/11 are unmistakable and unavoidable, from the sight of buildings erupting into balls of flames, to the onlookers' use of their cell phones to record the events, to people seeking shelter from the smoky debris closing in on the streets around them, to disquieting television news coverage by reporters who scarcely know how to keep their composure and handle what is unfolding before them. The results are alarming and nothing short of terrifying.

"Cloverfield" is filled with visions destined to seep into the viewer's memory and not let go, some of them involving the encroaching monster, seen at first in brief, scary flashes and later in all of its awe-inspiring glory, and others not—Rob's call to his mother as he and his friends seek safety in the underground subway is heartbreaking. Barely letting up except for in moments where the characters catch their breath or passingly connect as only human beings can in times of tragedy, the film pushes forward like a juggernaut, always prepared to pull something else out of its sleeve just when the audience thinks they can rest easy. Some might snuff at first when Rob insists on going deeper into the city to try and rescue his sort-of girlfriend Beth (Odette Yustman), who is trapped and injured in her apartment and may or may not still be alive, but it is presented in a plausible manner and allows for the viewer to question what they would do. If your own loved one was in the same predicament, most people, I suspect, would do what Rob does, the knowledge of uncertain death a non-issue.

For any picture relying on captured realism to such a heavy degree, it is imperative that the writing and acting are strong enough to not show the threads of what is, indeed, fiction. "Cloverfield" gets these things right, too. The dialogue is palpably felt and never contrived, director Matt Reeves confident enough to let the emotion of each situation speak for itself. As unfair as it is, none of the characters are safe; some die in an uncompromising instant, as it would actually occur. The performances from a cast of little-known or unknown actors, are first-rate, all of them superbly realized and empathetic without calling attention to themselves.

The conceptual design of the monster and its fruition via masterful special effects is better than one could imagine, a staggeringly eerie, full-blown original that is nothing, it turns out, like Godzilla. Save for a few on-the-fly theories that Hud throws out, its origins and motives are thankfully never explored. By retaining a complete air of mystery about what it is and where it comes from—which is how it would be if something like this ever suddenly occurred—the creature's threat is further heightened. As a tried-and-true genre piece, the film is drenched in atmosphere and the sort of tension you could cut with a knife.

Where "Cloverfield" goes one step further, however, becoming more than just a horror show, is in the scenes between Rob and Beth, shot a few weeks before, that bookend the mayhem. That the opening and closing moments, depicting the idyllic morning of and late afternoon that he took her to Coney Island, are in such sharp contrast to where these two characters' approaching fates ultimately end up is devastating. Their final recorded moments at the amusement park, the last images before the end credits, transform the film from a marvelously rendered monster-invasion pic into something so much more—an existential rumination on humanity in general, and the unforeseen and not always blessed turns life throws at all us. "Cloverfield" is the year's first unadulterated masterpiece.