The Other Boleyn Girl is based on a historical novel by Philippa Gregory, and it tells the story of the two Boleyn sisters who confused the heart of Henry VIII and brought about the downfall of Catholicism as the British religion of choice. Though one would assume that "the other girl" would refer to Mary (Scarlett Johansson), the sister who keeps her head, it's actually a phrase uttered by the more famous Anne (Natalie Portman). After seeing her younger, dowdier sister married ahead of her by their ambitiously idiotic father (Mark Rylance), Anne sees her prospects dwindling. Thus, Mary would be the successful sibling, and she would be the other one.

Except Daddy and paternal uncle Norfolk (David Morrissey) have other plans for Anne. Knowing that the Royal union between King Henry (Eric Bana) and Katherine of Aragon (Ana Torrent) is on the rocks after the Queen has failed once again to birth a living son, they decide to use Anne to capture the King's attentions. Only, Anne's over-eager approach backfires, and Henry decides the less flashy girl is to his liking. In one of the odder and strangely more effective screen seductions, Henry woos the prim and proper Mary by appealing to her second-child syndrome. Though Scarlett Johansson, who can rarely do wrong in this writer's eyes, reminds one of her fine performance in The Girl With a Pearl Earring here, her skills for subtlety are given sharper focus by the power of the torrents of passion this surrendering unleashes.

Mary giving herself to the King also unsheathes the movie's passions, and after a somewhat plodding first act, it serves as a starter pistol to finally get this race going. Pissed off that she keeps losing at every turn and misinterpreting her sister's accidental fortune as devious scheming, Anne decides that she will steal the King completely from both his wife and his mistress. Knowing that Mary's days are numbered since she and the King are not married, Anne plots to get a ring on her finger, thinking that all she'll need to do then is pop out an heir and her life will be set.

The Other Boleyn Girl is a film about the consequences of greed and ambition. As the disgusted mother of the two girls, Kristin Scott Thomas even asks when those traits stopped being sins and became virtues, unable to fathom the lengths her husband and brother will go to in order to gain wealth and power. The Boleyns all suffer, including brother George (Jim Sturgess, vying to take the same bland spot in casting director's hearts that James McAvoy has been comfortably resting in), whose latent romantic yearnings for his sister become another tool in Anne's game. The whole family crumbles. Only Mary manages to find her way through, having stayed true in spite of everything. (This is not a spoiler, kids, it's history.)

As I said, Johansson is quite good here, taking the more quiet role and even dressing down for the part. Eric Bana also turns in a solid performance as Henry VIII. Bana is best in thinking roles, and the Henry of Peter Morgan's screenplay is a brooding man given to ill humor. Morgan knows how to write about the heavy heads that wear crowns, having also penned The Queen and The Last King of Scotland, two films that I felt got close to the cigar but then couldn't strike the match. His Henry suffers a similar fate, being woefully underwritten. Though notorious for his overindulgence and inability to control his urges, the King's portrayal here is bereft of any complexity. He seems only capable of several shades of lust, nothing more. Bana tries hard to show a richer inner life, but the script lets him down.

Not that the director is any help. Subtlety does not appear to be Justin Chadwick's strong suit. Or maybe it's just that he's used to having more room to get where he is going, having earned his stripes on longer BBC dramas like the 2005 version of Bleak House. Otherwise, I'm not sure how to explain the storytelling shortcuts he takes in The Other Boleyn Girl. There are only so many times a director can fall back on stormy, time-lapsed skies to indicate emotional turmoil, or let a well-placed gong punctuate a scene, before it feels like he's cheating. Likewise the sudden shift to steadicam as a cheap substitute for tensions.

Not that I am completely dismissing The Other Boleyn Girl. Despite both the first and third act feeling overly stretched, the meaty middle act is quite good. As the more outgoing sister, Natalie Portman runs away with the whole shebang, turning Anne's initial defeat into a triumph with a wink and oodles of seductive charm. She is also blessed with a better arc than Johansson, whose character is knocked out of position while sick in bed. After taking control of the boorish patriarchs in her family and bringing England to its knees, Anne suffers a near complete breakdown, watching her carefully laid plan fall to pieces, and yet convincingly marshals her strength to stride defiantly toward the chopping block. It may be Portman's most demanding role yet, and she continues to prove she is far more formidable than your average ingénue.

When it's all said and done, The Other Boleyn Girl squeaks by on the strength of its acting talent and the fact that history often provides a story so good that even when a screenwriter and director messes it up, it's still impossible to get it completely wrong. (Granted, the Philippa Gregory source material does have its merry way with some of the facts, but as a plot about sibling rivalry and palace intrigue, the spine she provides the tale holds up.) Not as tasty as sitting down to a Royal banquet, but also not as painful as being the main attraction at a Royal beheading, The Other Boleyn Girl nestles somewhere very fine in the center.

Jamie S. Rich is a novelist and comic book writer. He is best known for his collaborations with Joelle Jones, including the hardboiled crime comic book You Have Killed Me, the challenging romance 12 Reasons Why I Love Her, and the 2007 prose novel Have You Seen the Horizon Lately?, for which Jones did the cover. All three were published by Oni Press. His most recent projects include the futuristic romance A Boy and a Girl with Natalie Nourigat; Archer Coe and the Thousand Natural Shocks, a loopy crime tale drawn by Dan Christensen; and the horror miniseries Madame Frankenstein, a collaboration with Megan Levens. Follow Rich's blog at Confessions123.com.