My Week With Marilyn

Where biography is concerned, movies are eminently unreliable. Portraiture is another matter — more beholden to personal expression than to fact, and maybe also inherently more movie-conducive. “My Week With Marilyn”  is not the place to go for a credible biography of Marilyn Monroe, but didn’t we already know that, and don’t we want something else anyway?

Adapted by Adrian Hodges from Colin Clark’s books, TV veteran director Simon Curtis’ film feels slight in a familiar way, as if seeming pitiably shallow were the consensus-mandated Monroe-bio boilerplate. The movie lacks plausible narrative tension — its conflict is readymade and perfunctory — but powers itself by the different kind of tension that arises from watching Michelle Williams sustain so finely detailed an impression for so long. Best to see it as simply a showcase for one more portrait of the alluring screen icon.

The framework is this: While working for an increasingly exasperated Laurence Olivier (Kenneth Branagh) in 1957, Monroe gets a brief tour of England from an eager young production assistant (Eddie Redmayne), who happens also to be our discreet first-person narrator. It is he who summarizes this as the case of a great actor and a great movie star wanting to osmose each other’s gifts but struggling together in a film that won’t do that trick for either of them. (It is called “The Prince and the Showgirl,” after all.) As for our anecdotist’s relationship with Monroe, that develops expectedly: he’s helplessly smitten, she’s inadvertently a tease. Touchingly, they manage to treat each other with kindness.

If we now can agree that celebrity itself is a laudable and costly talent, we must consider Monroe’s career among the first tests of that axiom. The makers of “My Week With Marilyn” might have been more adventurous, abandoning the pretense of plot altogether, but old-fashioned movie storytelling also is their given milieu, a tolerable if trite concession.

Redmayne is a gracious cipher, just as Judi Dench and Emma Watson are generously forgettable in peripheral supporting roles, along with Julia Ormand and Dougray Scott as variously vexed famous spouses Vivien Leigh and Arthur Miller, respectively. Branagh, shrewdly aware of the generational baton-passing that keeps movie glamour going, clearly enjoys himself. But as someone says, “When Marilyn gets it right, you just don’t want to look at anyone else,” and all that really matters here is how well Williams plays that.

Bodily beauty is not the first association we might make with Williams, who has seemed twiggy and swaddled in recent films. Did she steal this job from a curvier actress? In any case, she has earned it: In good time and in good proportion, we glimpse both the effort required to maintain the Marilyn persona and the reasons why a woman — perhaps any woman — might endure such effort. It’s a good performance not just because it transcends mimicry but also because it seems like a personal and self-justified investigation. Appealingly, it’s as if Williams is doing this not just for us, or for Monroe, but for herself.