Anyone doubting the layered, nuanced, and heartbreaking acting abilities of Michelle Williams will find My Week with Marilyn a tremendous revelation. And Williams fans will enjoy it even more. In My Week with Marilyn Williams takes on the formidable challenge of playing Marilyn Monroe, and does so with depth and assuredness, and without resorting to caricature. Williams's Marilyn commands the screen with pain and delicacy, and doesn't let go until the final credits. My Week with Marilyn focuses on a small time frame in Monroe's life, right after her marriage to Arthur Miller. Monroe, already "the world's most famous woman," still feels the need for validation as an actress. What better way to achieve that, she believes, than committing to costarring with Laurence Olivier in The Prince and the Showgirl, a film she firmly believed would finally cement her reputation as a serious actress. My Week with Marilyn is based on the short memoir of Colin Clark, a crew member on The Prince and the Showgirl, who quickly became the confidant of the wildly insecure Monroe and watched a train wreck of egos--mostly Olivier's and Monroe's--collide in a fiery near-disaster. Kenneth Branagh gives an uncharacteristically restrained performance as the exasperated Olivier, resentful of the "new blood" in Hollywood that the young Monroe represents, and disdainful of her cult-like devotion to Method acting. (And of Monroe's chronic tardiness, which threatens to undermine the veddy, veddy strict British work schedule.) Eddie Redmayne plays Clark with a sweet, gentle veneer, someone who grows to care genuinely about the complex Monroe. Julia Ormond is clipped and proper as Olivier's then-wife, Vivien Leigh, and Emma Watson shows a lovely gravitas as Lucy, Monroe's acting coach. But it's Williams who gives the revelatory performance, capturing with painful intensity the insecurity that begins to seep out of Monroe like a fearful sweat. "Excuse my horrible face," she blurts out, while looking nothing less than her usual radiant self. Where does this tragic insecurity come from? My Week with Marilyn doesn't attempt to answer the unanswerable, but instead shines a light on the very real woman who became lost in the giant shadow of legend. --A.T. Hurley