Breakout Actors in Summer Movies By Mekado Murphy Breakthrough Performances: Dennis Lim looks at some of the noteworthy performances of the summer movies season. Léa Seydoux, "Farewell, My Queen" At 26 the French actress Léa Seydoux already has a foothold in the rarefied world of auteur cinema and the crossover realm of the blockbuster. She began her career in the nervier sectors of French film, working with Catherine Breillat, Bertrand Bonelloand Christophe Honoré. Mr. Honoré"s "Belle Personne" won her a César (the French Oscar) nomination for most promising actress in 2009, and she has since made a considerable dent in the Hollywood consciousness, last year seducing Owen Wilson in "Midnight in Paris" and plotting to kill Tom Cruise in "Mission: Impossible - Ghost Protocol." It doesn't hurt that fashion designers and editors love her (she was the face of a recent Prada campaign), and that the movie business is in her blood. Her grandfather is a chairman of one major French film company, Pathé, and her great-uncle is the president of another, Gaumont. You could say that Ms. Seydoux's lead role in Benoît Jacquot's "Farewell, My Queen" (opening July 13) marks the coronation of a rising star, even though she plays not royalty but a Versailles courtier on the tumultuous eve of the French Revolution. Based on a 2003 novel by Chantal Thomas, the film takes the "Rosencrantz and Guildenstern" tack of retelling a classic drama from the occluded vantage of a supporting player. The official reader to Marie Antoinette (played by Diane Kruger), Ms. Seydoux's character, Sidonie, loyally tends to her flighty mistress's every whim, scurrying down long corridors on impromptu errands, even as news circulates that the Bastille has been stormed and a hit list issued. Heads will roll, as we know, but Sidonie keeps hers. Careful not to betray her anxiety over the looming upheaval or her envy of her beloved queen's favorite lady-in-waiting (Virginie Ledoyen), the solemn, attentive Sidonie gives Mr. Jacquot's costume drama its center of gravity and its modern edge. Many of Ms. Seydoux's previous roles have called on her to project an almost sullen poise, and here she transforms her cool gaze into a radiant watchfulness, conjuring an intensity of devotion that is a reason for being. Anders Danielsen Lie, "Oslo, August 31st" The suicidal mind can be something of a trap for actors and filmmakers: those who enter it run the risk of romantic clichés and trivializing explanations. But Joachim Trier's "Oslo, August 31st," which opens with its protagonist trying (and failing) to drown himself, never turns into a simple "will he, won't he" proposition. And as it unfolds, over a beautiful late-summer day and night, it becomes as much about life, loss, memory and the passage of time as the inexorable pull of death. A film that registers moment-to-moment mood shifts just as it records subtle changes in the light, "Oslo, August 31st" (May 25) depends mightily on the fine-tuned performance of its lead actor, Anders Danielsen Lie, whose depressed, barely recovering drug addict, Anders, seems at times like an impenetrable enigma and at others like an exposed raw nerve. Moviegoers who saw Mr. Trier's first feature, "Reprise" (2006), will remember Mr. Danielsen Lie as one of its two novelist friends, the one who shot to early success and almost immediately suffered a nervous breakdown. This gaunt, lanky actor brings a similar intensity and searching intelligence to "Oslo, August 31st" (loosely adapted from the French novel "Le Feu Follet," which inspired an earlier film by Louis Malle). Ten months clean and only weeks away from completing a drug rehabilitation program, Anders is spending the day in Oslo, and his back story and the extent of his pain emerge in a series of awkward encounters. A job interview goes off the rails when he's asked about the gaps on his résumé. His sister declines to see him, suggesting the depths of the family scars. A visit to a close friend reveals the tedium of domesticity, an ambiguous ideal that in any case remains out of reach. It bears noting that off screen Mr. Danielsen Lie, 33, is an almost absurd high achiever: a practicing physician (who put in time at an addiction clinic while researching the role) and a singer-songwriter (who last year released his first record, a concept album called "This Is Autism"). Anders, on the other hand, is a privileged screw-up, who could and did rely on family and friends when nearing bottom and became an enormous psychic burden to many of them. Mr. Danielsen Lie isn't afraid to reveal Anders's uglier tendencies, but in capturing the character's tragic self-awareness and his profound loneliness, he also shows us the depths of his alienation, not least from his own life. Dwight Henry, "Beasts of the Southern Wild" Among the many improbabilities of Benh Zeitlin's Sundance hit "Beasts of the Southern Wild," not least is that its two lead performers are a 6-year-old girl and a beloved New Orleans baker, neither of whom had acted before. Pitched as timeless myth as much as post-Katrina allegory, "Beasts of the Southern Wild" (June 27) revolves around the ragtag inhabitants of a southern Louisiana bayou village on the wrong side of a levee, bracing for an all-but-biblical flood and coming together in the aftermath. While the movie's imaginative flights, its visions of ecological apocalypse and furry ice-age creatures come from its precocious heroine, Hushpuppy (Quvenzhané Wallis), it's the little girl's ailing father, Wink, played by Dwight Henry, who provides its anguished heart. Mr. Zeitlin found Ms. Wallis through the grueling process of auditioning more than 3,000 candidates over a nine-month period. But for the role of Wink, he gravitated to Mr. Henry, a charismatic chef whose determination to stay and rebuild after the devastation of Katrina mirrored a major theme of the film (and whose pastries and soul food Mr. Zeitlin and his associates knew well). Mr. Henry had just opened a new shop (his first was destroyed during the hurricane) when he was offered the role in "Beasts," and his busy schedule required a whirlwind of multitasking, working with acting coaches in the pre-dawn hours as he prepared his bakery's signature doughnuts.