In light of Casey Affleck's recent admittance that his supposed Joaquin Phoenix documentary "I'm Still Here" was completely staged, the debate is heating up over whether or not the purportedly true "Catfish" is also a fake. In this film's case, it doesn't really matter. If it is a real documentary—and the filmmakers are adamant that it is—it's staggering and miraculous, lightning in a bottle personified. If it's fiction, then directors Henry Joost and Ariel Schulman are, indeed, exquisite filmmakers who ought to have first pick on a follow-up project. Either way, it's a truly exceptional piece of work, a ravenously fascinating motion picture that offers up a one-of-a-kind viewing experience fraught with what might best be described as a roller-coaster of emotional responses. Sweet-natured amusement at the onset eventually makes way for a high-wire act of intrigue, disquieting tension, and heartbreaking pathos. Watching it has the power to simultaneously chill the bones and break one's heart.

When a picture of a ballet dancer taken by aspiring photographer Yaniv "Nev" Schulman is printed in the New York Sun, it catches the eye of a talented 8-year-old painter named Abby. Hailing from the small town of Ishpeming, Michigan, Abby begins mailing Nev impeccable artwork of his photographs. As Nev's Facebook (and later phone) correspondences grow between himself and Abby, her mother Angela, and 19-year-old half-sister Megan, it is all captured by the curious cameras of Nev's brother Ariel Schulman and friend Henry Joost. Flattered by the attention and floored by Abby's artistic talent, Nev's electronic relationship with the family grows—he even embarks on an internet romance with talented wannabe musician Megan—until a little digging leads him to discover they aren't being completely honest with him. Now feeling betrayed and wanting to get to the bottom of what could possibly be a scam, he decides to track them done at their home address and surprise them in person.

"Catfish" is mesmerizing, an honest, uncompromising comment on electronic human connection in a twenty-first century world. Anyone who regularly uses the Internet has probably developed some form of a relationship online with another individual they do not personally know. Whether it just be a case of two people exchanging e-mails about a shared interest or a full-on romance complete with IMs and late-night telephone chats, the truth of the matter is that, without direct person-to-person contact, there is no way of telling if the other person is being truthful about who they are and what their motives might be. "Catfish" gets to the heart of this topic with gloriously unsettling results and could make for an ideal companion piece to 2006's "The Night Listener," just about the only other film that comes to mind dealing with a similar premise.

The first act is light and entertaining as Nev starts receiving gorgeous painted canvases based on his photography. Naturally, he gets a kick out of a such an unlikely fan in 8-year-old Abby, and the well-paced extended montage that ensues, scored with a lovely ethereal cover of The Beach Boys' "Good Vibrations" by 1970s' children's choir The Langley Schools Music Project, keeps things rolling at a compulsively watchable pace. Slowly but surely, subtle signs point to something possibly being amiss in their exchanges, with Angela never able to put Abby on the phone (she is always gone, or sleeping, or busy). Eventually he does get to briefly chat with Abby, but the conversation is short and awkward. The big kick, though, comes when Nev does some research and discovers Megan's songs are actually cover recordings from other people that she has stolen and tried to pass as her own. As for the building space the family has said to have bought with the intention of housing a gallery of Abby's art work, a little digging reveals the space has been empty for years with no signs of anyone leasing it out. Following an assignment in Colorada, Nev (with Ariel and Henry in tow) decides to make a pit stop on the way back to NYC in Ishpeming, Michigan.

What happens next would be a crime to reveal, although it deserves to be said that the trailers and marketing campaign for "Catfish" have been mighty deceptive in passing it off as a horror-thriller, complete with quotes comparing it to Hitchcock and ominous nighttime shots of Nev peeking through the windows at Megan's dark, desolate horse farm. Yes, it is true that the picture does have an unnerving, edge-of-your-seat quality to it in the second half, but for an entirely different reason than the trailers are suggesting. The movie isn't about spooks or things going bump in the night, but about the mysteries of real-life unknowns and, eventually, the power of electronic illusion and the struggle to find contentment in a life that hasn't turned out as one had expected. Directors Ariel Schulman and Henry Joost deliciously—and ever so deliberately—peel back layer upon layer of artifice to arrive at a conclusion that is genuinely poignant in its generosity and deftness for human empathy. But not so fast; there are further revelations right around the corner.

Viewers who have been led astray and walk into "Catfish" expecting a scary movie in the vein of 1999's "The Blair Witch Project" or 2010's "The Last Exorcism" will be in for a kind of surprise they don't expect that has nothing to do with the film's fright quotient and everything to do with its promotional mislabeling. If they open themselves up to other possibilities, however, what they will find is a story of captivating depth and unlikely compassion that is just as satisfying, if not more so. As a documentary that took on a stranger-than-fiction allure as the filmmakers continued recording, "Catfish" is close to revelatory for the format. No matter how hard anyone tried, its unique windfall of a narrative couldn't be duplicated.