HOLIDAY ARRIVALS

“My Week With Marilyn,” starring Michelle Williams as the blond bombshell, is as mercurial a film as its subject, Marilyn Monroe, was a star. It’s lush and vibrant when Williams is onscreen, mostly fussy British discontent when she’s not.

Whatever the flaws, the truth is nothing else much matters since Williams is Marilyn, and Marilyn had a way of outshining everything around her. It is magnetic to watch the actress move seamlessly between the many faces of Monroe, the movie star she became, the wounded girl she was growing up. Capturing those changing moods was challenging enough -- a sort of internal on-off switch was required. But it is in revealing the complicated enigma of Monroe’s character, the intelligence that was always lurking behind the sexy pouts and poses, the unquenchable need for reassurance, that Williams is divine.

The story is a true one, based on the diaries of the late arts documentary filmmaker Colin Clark. It was directed by Simon Curtis, a veteran of the U.K.’s classier TV-movie stream, with screenwriter Adrian Hodges, who co-wrote 1994’s “Tom & Viv,” adapting. The week in question is slight, a few minor days in the life of a megastar, and the director treats it as such.

Clark, played with great charm and cheek by Eddie Redmayne, chanced to have a working flirtation with Monroe in 1956 when he was 23. She was in London to film “The Prince and the Showgirl” opposite the great British thespian Laurence Olivier in hopes Hollywood would take her more seriously. Clark was the film’s third assistant director, a grand title for his job as Olivier’s gofer. For a few days, he became Monroe’s chief ally on and off the set, and he did not forget a breathless moment of his time with the movie star or the details of the movie-making.

“My Week” moves between Monroe’s friction with Olivier (Kenneth Branagh) during production, her struggle with depression away from the set and the machinations of the small circle of sycophants always around her. A clearly smitten Clark becomes her shoulder to lean on, a trusted advisor, and her co-conspirator in escaping, at least briefly, the star machine.

The whole notion of “movie star” as we think of it now -- all the adoration and attention, some welcome, some not -- was just beginning to congeal in a significant way back then. Using Clark’s observations, that cultural shift almost comes to life in the film -- the claustrophobic crush of fans, the press of the celebrity press and her own ambivalence about it.

The movie Olivier and Monroe were working on in ’56 was a light comedy. Curtis gives us a faithful representation of a film that wasn’t very good even then. Its most memorable scene -- the showgirl caught unaware in a bouncy dance -- is as daffy and delightful here as it was in the original. But as soon as Monroe’s out of sight, the film within the film turns tedious and flat.

A jowly Branagh plays an overbearing Olivier, who is playing an overbearing prince of a fictional Balkan kingdom in “The Prince and the Showgirl” -- strangely, he’s better as the prince than as the legendary actor. In contrast, Judi Dench is portraying the acclaimed stage actress Dame Sybil Thorndike, who is cast as the addled Queen Dowager -- and any way you cut it, her moments are among the brightest in either film.

There are all the other tension-inducing players in Monroe’s life -- the churlish new husband, Arthur Miller (Dougray Scott); the antsy business partner, Milton Greene (Dominic Cooper); the brown-nosing acting coach, Paula (Zoe Wanamaker). But they are brushed past so lightly you wonder if it might have been better to drop them entirely.

With all those personalities and Olivier such a pain, you can’t blame Monroe for wanting to escape. And with Clark’s help, she does, and this is when the film is at its most endearing. A week, and one particularly enchanting day, that begins with the royal library and ends with a skinny dip in the Thames. It gives us a rare glimpse of Monroe trying on an ordinary life for a change. But like Clark, it’s only a brief flirtation; she simply can’t resist the affection of a crowd.

Catching all of those light and dark shades is director of photography Ben Smithard (“The Damned United”). He shoots Williams like Monroe -- as if the camera cannot get enough of her, as if there is no bad side. He gives Redmayne almost equal treatment, so that you understand why Monroe would be drawn to Clark, would want to bask for a while in his schoolboy crush. Redmayne manages to look smitten but not silly, adoringly attentive but not cloying.

For Williams, despite a string of exceptional performances, “Blue Valentine” and “Brokeback Mountain” among them, it was a risky gambit taking on such an iconic star, one who had such luminous power on screen, such a heartbreaking story off. One that certainly paid off. It’s hard to imagine a more unforgettable Monroe than the one Williams has given us -- except for the original, of course.

--

betsy.sharkey@latimes.com

--

‘My Week With Marilyn’

MPAA rating: R for some language

Running time: 1 hour, 41 minutes

Playing: In general release