There is a moment both saddening and comic in “Married Life,” a new film by Ira Sachs, who you don’t know because until now he hasn’t existed. A wife starts sobbing because her husband says he no longer loves her, and he calls the doctor, mistaking her emotional anguish for the symptoms of a heart attack. This obvious kind of disconnect is central to the movie’s tagline: Do you really know what goes on in the mind of the person with whom you sleep?

That’s a pretty clunky tagline, but it is appropriate for a movie that, despite an all-star cast and gorgeous cinematography, winds up clunky itself. Pierce Brosnan, Chris Cooper, Patricia Clarkson and Rachel McAdams weave around one another in a plot of infidelity that aims for intrigue and complexity but comes closer to dull predictability. Harry (Cooper) has taken to cheating on his wife Pat (Clarkson) with the younger and more alluring Kay (McAdams) while his friend Richard (Brosnan) watches from the sidelines and eventually throws himself into the romantic mix. Brosnan, with a perfect and incredibly sexy British accent, narrates the drama like a detective in an old film noir.

This use of Richard as the omniscient narrator gives “Married Life” its most redeeming quality: a look at the two sides of a given relationship. Richard’s descriptions control our perception of all characters and block the audience from forming personal opinions about the man or woman on screen. “This is my friend Harry Allen,” Richard begins, “He likes his wife. It can happen.” He is in total control of how Harry feels (he likes his wife) and how Harry fits in with society (he is the exception, not the rule). And as the characters go about their daily routines, kissing hello and goodbye and exchanging “I love you”s before bed, Richard points out that the husband doesn’t really love the wife, he loves another woman half his age. His narration drapes jaded cynicism over the empty, vapid actions of characters locked in by delusion.

And what plentiful delusions! In an opening sequence, Harry and Richard have lunch in a clubby, wood-paneled, smoke-filled restaurant and discuss their love lives. Harry intimates that he is unhappy with his marriage because love, to his wife, is all about sex. The ensuing dialogue is extremely hard to buy. Grown, middle-aged men speaking about sex in such a frank manner over steaks and martinis is — let’s be honest — implausible. The dialogue goes on to establish that Harry’s conception of love — an intense emotional co-dependency — clashes with his wife’s. The respective spouses, each convinced they have it right, attempt to find other people to love in their own, satisfying ways.

But all the other characters have their unwavering sets of beliefs, too. Kay, though pretty and bubbly, has a Florence Nightingale complex and sees a lover as a wounded object to heal and repair. The main characters can’t seem to find satisfaction in one another, no matter what the current permutation of partners, and they are unable to move beyond their own little world to seek out new lovers. Richard’s narration isolates his peers from the outside world; though the clothing and hair indicate an earlier era, barely any mention is made of the very recent World War II or its sociopolitical fallout. He knows he can manipulate those around him and, as the movie progresses, he forces the other characters to stay locked in by their delusions. His smooth, sultry voice-over only reinforces the sense that he is firmly in control.

The inability of any character to move beyond this tiny circle — there are really only four or five people in the movie — means that, despite a rich pool of talent, there is a certain listlessness and lack of motivation to the acting. Clarkson is very good at being stiff and awkward, and Cooper’s tears and hound-dog eyes are very real looking. But one simply cannot believe they have cause to be so awkward or so sad; the film’s narrow scope leaves little room for explanation by way of impetus or context. Both lovers and lines (the phrase “burden of conscience” is overused) are passed from character to character, and an audience can guess early on who will end up with whom. The climax of the movie consists of Harry finally figuring out what the audience knew all along. The anti-climactic ending (dramatic irony isn’t dramatic) leaves something to be desired.

The raw talent is here, but the execution is unconvincing because of Richard’s crippling ability to control. No real action occurs when it all filters down through his voice and perspective, no matter how beautiful the lighting (quite) or how good the accompanying music (also quite). T.S. Eliot had the general idea: Between the idea and the reality — between the motion and the act — falls the shadow … of Pierce Brosnan.