To some degree, it seems strange that Knight and Day even exists. It doesn't seem strange that there is a romantic action/comedy starring Tom Cruise and Cameron Diaz; it's frankly a little surprising it took them this long to make one. What's odd is how little attention was paid to it, and how quickly it was forgotten. Just for fun, try asking the next person you see what Knight and Day is, and watch the blank looks you'll get in response. Five years ago, understand, this movie would have been epic; it would have been the biggest movie of the summer. In 2010, in opened in third place. Behind Grown Ups, for Chrissakes. Its domestic numbers were barely better than those of Killers, which was basically a JV version of the same movie.

So why did it underwhelm? Some blamed the generic title (seriously, that could be a title for any story, and has precious little to do with this one), or the forgettable marketing campaign (which seemed bound and determined not to exploit the recognizable faces of its fading stars). But the conventional wisdom, which may very well be true, is that Tom Cruise and Cameron Diaz simply can't open a movie anymore, even teamed up in a popcorn-friendly package. Tastes change, audiences are fickle, and there you go.

But what of the movie, you ask. Well, it feels kind of like what it is: a filmed deal, slick and engineered, trying perhaps a little too obviously to be mirthful and high-spirited. Is it enjoyable? In spots, absolutely.

We'll skip the plot summary altogether; they don't appear to pay it much mind, so there's no good reason that we should. The thin story primarily exists as the bulletin board on which to tack set pieces and romantic interludes; director James Mangold is going for a fast-paced, elegant globetrotter in the Hitchcock style, complete with a McGuffin for everyone to pursue (here it's "the zephyr," a self-sustaining energy source the size of a 9-volt battery). Our heroes zig-zag from Wichita^*. to Boston to the tropics to Austria to Spain, dodging bullets and trading quips and falling in love.

It's all highly constructed and more than a little convoluted, but that's not an insurmountable issue; the same could be said for To Catch a Thief or North by Northwest. The trouble may very well be that Mangold plays it too straight--he's skilled, and has got a light enough touch, but he's not a stylist, which is what a movie this preposterous needs. His best films (Walk the Line, Cop Land, Girl, Interrupted) were firmly tethered in the real world; he doesn't have the right goofy energy to bring this material off. He's also undone by some of the worst CG action sequences in recent memory. The emergency landing of the commercial jetliner is patently unconvincing, and the same goes double for the car chases, in which people leap around like animated characters and the vehicles jump and roll like they're in a video game. You can do ridiculous stunts and have them look convincing--the James Bond movies used to do them all the time. These action sequences are borderline laughable.

Performances are hit and miss. Viola Davis is too interesting an actor for a role this dull, and I don't know what the hell accent that is that Peter Sarsgaard's doing, but I'm not buying it. But Paul Dano isn't playing an irritating mope, for once, and fills his role nicely. Diaz is passable--she isn't asked to do much, and doesn't, really. (She really should have convinced someone to eliminate just a few of those scenes where she has to talk to herself, which people never actually do.) That leaves Cruise to carry most of the weight--which he does, surprisingly enough. The guy may be certifiable, and a few years past this kind of roguish hero bit, but damned if he doesn't deliver; it's a rich and clever comic performance, delicately dancing the line between dangerous and funny ("I'll kill myself, and then her!"). His Roy Miller is a confident optimist, giving his frightened companion constant reassurance (when they're kidnapped, she wakes up to find him shirtless and bound, swinging upside down; he gives her a cheerful "I know this looks bad!"), though prone to bouts of amusing petulance when he's questioned. His chemistry with Diaz is good (they previously appeared together in Vanilla Sky), though their beach-fight-turned-flirt is painfully awkward. Through the rest of the film, though, they're believable enough--they look great together and develop a nice rhythm, and that's pretty much the job here.

Knight and Day arrives on Blu-ray in a three-disc set, with the film and bonus features on a Blu-ray disc, the film on a standard-def DVD, and a third digital copy disc for transfer to portable devices.

The MPEG-4 AVC transfer nicely spit-shines the movie's slick, glossy sheen. It's a clean, attractive image with nothing particularly objectionable--color saturation is full (Diaz's deep blue eyes are particularly lovely, and the tropical exteriors are punchy and lush), black levels are deep and inky (particularly in the nighttime sequence after the plane crash), and detail work is impressive.

The slam-bang English 5.1 DTS HD Master Audio mix is tight and exciting, slamming effects throughout the soundstage without overwhelming the clean, distinct dialogue channel. Separation and directionality are especially strong in the car chases and warehouse shootout, with gunshots sharp and piercing in the surround speakers. It's a full, active mix, immersive and involving.

Spanish and French 5.1 Dolby Digital options are also offered.

Considering the slickness of the film itself, it shouldn't come as a surprise that the featurettes are basically studio puff pieces. Take the action featurette "Wilder Knights and Crazier Days" (12:30) Did you know Tom Cruise does his own stunts? That Cameron Diaz does her own driving? Everyone talks in sound bites and it's cut with the precision of a political ad; the behind-the-scenes footage is entertaining, but this is definitely a sell job. "Boston Days and Spanish Nights" (8:10) focuses on the extensive location work and production design with about the same depth.

"Knight and 'Someday': Featuring the Black Eyed Peas and Tom Cruise" (9:09) shows Cruise and his wife "Kate" Holmes traveling to a Black Eyed Peas concert in London to meet the band and hear their end credit song; fans of the band (they have fans, right?) might enjoy it, but everyone else should pass it by. Next are a pair of Viral Videos--one of Cruise and Diaz playing soccer on the set (1:10), one of the duo doing fight choreography (1:18)--and, I'm sorry, you can't just decide that something is a viral video, especially such staged and phony clips as these. "Knight and Day: Story" (3:50) and "Knight and Day: Scope" (3:05) are basically extended commercials, recycling many of the same sound bites as the longer featurettes (I'm very tired of hearing Cameron Diaz say she's been making movies for 15 years).

A Theatrical Trailer (2:26) and Digital Copy "How-To" (3:35) are also included.

Knight and Day works very hard to look breezy, and you can see the flop sweat all over it. But Cruise is continuing to develop his comedic chops; his performance has an effortlessness and unpredictability that the picture itself never quite nails. His charm eventually takes the film over; Knight and Day isn't a great movie, not by a long shot, but it's a decent enough piece of popcorn entertainment.

Jason lives in New York. He holds an MA in Cultural Reporting and Criticism from NYU.