Love stories needn't reinvent the wheel as long as they treat their characters—and the audience—with respect. A little chemistry doesn't hurt, either. For all of its occasional taxing delusions of grandeur, "The Vow" gets these two things right, writer-director Michael Sucsy (2009's HBO telepic "Grey Gardens") and co-writers Mark Silverstein and Abby Kohn (2009's "He's Just Not That Into You") allowing the story and relationships to develop naturally rather than force them down contrived avenues. This is an important point because, in essence, it symbolizes the journey that Leo (Channing Tatum) and Paige (Rachel McAdams) must go on when an accident tears their world apart and strips one of them of any memories from the last five years of their life.

One minute they are driving home from a movie at Chicago's Music Box Theatre on a frigid, snowy night, and the next a plow truck has rammed into the back of them without warning. Leo, who was wearing his seatbelt, gets away with superficial bumps and bruises, but Paige, who happened to have just taken hers off, is put into an induced coma after receiving serious brain trauma. When she finally wakes, Leo is dismayed to find that his wife not only doesn't remember who he is, but seemingly has lost all her memories since before she quit law school to pursue sculpture at the Art Institute of Chicago. Paige's well-off parents Rita (Jessica Lange) and Bill (Sam Neill), whom she has been estranged from for reasons she doesn't quite understand yet, are suddenly back in the picture, hoping to rekindle things and set her back on the path she once was headed down years before. To deny the decisions she made after this point simply because she can no longer remember them seems terribly wrong to Leo, though, a betrayal of both her distant past and her present existence. Risking his livelihood and career as the bills stack up (he owns a professional recording studio), Leo makes it his mission to get Paige to fall in love with him again.

Narration is a technique rarely ever necessary in film. Unless it is genuinely helping to inform the viewer of a character's internal self and values, as it does in, for example, 1986's "Stand by Me," it usually comes off as a screenwriter's lazy way to establish information by telling rather than ideally showing. Or, in the case of "The Vow," it is used for more pretentious purposes where highfalutin ideas are transformed into strained, overly wordy philosophical mumbo-jumbo about how crucial certain moments are and how we are all just the sum of all our past experiences added up. What said voiceover has to say might be right, but it doesn't fit in a film that otherwise would have made the same points without spelling it out. The narration, bobbing in and out throughout, calls attention to itself because of its artificiality in the shadow of a romantic drama that more often than not strikes truthful notes. The picture as a whole is not ruined by it, but it would be even better without it.

Though only brief snapshots of Leo's and Paige's life before the accident are shown, including their initial "meet-cute" at the MVA, first date, and wedding day, it is enough to sympathize with Leo's feelings of betrayal when Paige can't remember him or the last four years they've shared together. Simultaneously, the film is well aware that Paige's memory loss is not her fault, and her subsequent feelings of not belonging and struggling to reconnect with a world she knows nothing about while also not fully understanding why she left behind her former ambitions, friends and family, and ex-fiancé Jeremy (Scott Speedman) are thoughtfully portrayed. The conflicts that arise when Leo and Paige clash seem authentic, both of them acting out of fear and sadness, but never rash self-destruction. When they have a problem, the screenplay forces them to really speak to each other rather than act like hair-brained pawns, and this extends to the side players, too, including the way a secret is handled that Paige ultimately discovers her family has been keeping from her.

At this stage in their still-young careers, Rachel McAdams (2010's "Morning Glory") is probably a more skilled actor than Channing Tatum (2011's "The Eagle") is, her every moment on screen one that is believable, natural, and emotionally at the heart of who she is playing. Tatum isn't quite as seemingly effortless, but he makes up for any signs of intermittent stiltedness with the sincerity of a guy who unequivocally adores his on-screen partner. For this, McAdams and Tatum make a memorable couple, not merely lovers but soul mates worth rooting for. When Leo tries to recreate their first date and takes her to Café Mnemonic (a fitting name if there ever was one), it's a sweet and joyous moment, the kind that only occur in cinematic romances that are clicking just as they should be. As Paige's decidedly overbearing parents, Sam Neill (2010's "Daybreakers") and Jessica Lange (2003's "Big Fish") deceptively play their early scenes with little range and depth, only to reveal unexpected shades of themselves the longer things progress. For starting the film off as one-note shrews, it is appreciative to see them become people rather than remain villains by the end. Of special note in a fairly standard supporting role that she far exceeds, Tatiana Maslany (2008's "Flash of Genius") is a fresh, soulful find as Lily, Leo's colleague and confidante at their recording studio. Maslany listens very well, and when she speaks the viewer has no choice but to want to listen to what she has to say. On the evidence here, she deserves to have a bright career ahead of her.

Overplayed melodrama is mostly, if not always, kept at bay in "The Vow," which takes a more unassuming approach to its storytelling. The soundtrack, aided by lush location shooting in Chicago courtesy of cinematographer Rogier Stoffers (2011's "No Strings Attached"), is well-chosen with pop tracks that compliment the goings-on without overstating matters (The Cure's "Pictures of You" is perfect for the final fade to black). Meanwhile, the way the narrative untangles its web in the third act is close to sublime in its logic. The key, Leo learns, is not to push Paige into remembering all the things that were once special to her, but to let her rediscover them on her own. If she made the right choices to begin with, then she'll make them again in due time; she's simply a few years behind. "The Vow" was inspired by a true story, the real-life couple appearing in a closing photograph that reveals they now have three children together. They might not look anything like Rachel McAdams and Channing Tatum, but even regular people sometimes get to have Hollywood-style happy endings.