Hollywood sex icon Marilyn Monroe brought her famous wiggle to England in 1956 to film The Prince and the Showgirl with acting legend Sir Laurence Olivier, her aging co-star and fearsome director. As Olivier's third assistant director, Colin Clark, then 23, had the delicious chance to observe the fireworks on set and (he claims) in MM's bed. Clark's memoir is the fragile foundation for My Week With Marilyn, a slyly comic meditation on stardom that owes less to screenwriter Adrian Hodges and director Simon Curtis than to the powerhouse at its center. The luminous Michelle Williams goes bone-deep here. Monroe's beauty was one of a kind. No one, not even Williams, can act it. What Williams does, with fierce artistry and feeling, is illuminate Monroe's insights and insecurities about herself at the height of her fame. Her scenes with a superb Kenneth Branagh, his wit martini-dry as the thin-lipped, defensive Olivier, ignite. Less potent is Monroe's flirtation with Colin (Eddie Redmayne, solid nonetheless). It took a toll on Monroe to look effortlessly buoyant on camera. Williams lets us see why. It's a great, soulful performance. Sit back and behold.