Born Margaret Grace Denig in Columbus, OH she was one of three children born to her parents, Rick and Linn Denning. She took to acting while she was growing up in the Columbus suburb of Worthington, and was featured in numerous regional productions. At age 16, Grace and her mother headed for Los Angeles, where she underwent the usual route followed by all aspiring actors - scads of rejections and income struggles. She landed her first on-camera experience in 2001 with "Rachel's Room," an Internet serial produced by Sony Digital Entertainment. Grace played the title character, a teenaged girl who chronicled her daily angst over parents, boys and school on her home video camera. For this project and all subsequent appearances, she utilized her stage name, Maggie Grace.She earned her big break the following year by playing doomed teenager Martha Moxley, who was murdered by Ethel Kennedy's relative Michael Skakel in 1975, in the TV-movie "Murder in Greenwich" (2002). The exposure afforded by the production, which was released a year after Skakel's conviction for the crime, led to more TV work for Grace. She was Tom Selleck's rebellious daughter in the TV-movie "12 Mile Road" (2003) and enjoyed a recurring role as Swedish teen Elke, who left "Oliver Beene" and his brother hot and bothered on the short-lived period sitcom. After "Beene" wrapped, Grace moved into the next phase of her career with the game-changing "Lost" (ABC, 2004-2010). Initially viewed as an irritant and a bit of a tease on the popular show, Grace's Shannon won favor from audiences for her tart tongue, which spared none of her fellow survivors from Oceanic Flight 815. She also enjoyed a juicy back story with her step-brother Boone (Ian Somerhalder), whom she had conned into buying off her boyfriends with outlandish tales of abuse, only to secretly take half of the hush money. Despite her unpleasant behavior, Boone harbored a long-simmering crush on Shannon, which she further exploited by sleeping with him.After the crash that launched the main plotline of "Lost," the daily struggle for survival - as well as the discovery of dangerous "Others" on the island - helped to ground Shannon and slowly peel away her childish layers. Her relationship with Boone, who was also stranded on the island with her, went through several paroxysms of change, especially after she became involved with another survivor, Iraqi soldier Sayid (Naveen Andrews). Boone's death at the hands of the island's resident mystic/crackpot Locke (Terry O'Quinn) further grounded her, but the new Shannon was not long for the show's quixotic world - after declaring her love for Sayid, she was shot by a member of another group of survivors. As with all of the character deaths on the series, Shannon's demise came as a particular shock to the growing legion of "Lost" fans.The near-universal success of "Lost" landed Grace a Screen Actors Guild Award for Outstanding Performance by an Ensemble in a Drama Series in 2004, as well as a Teen Choice Award nomination the following year. It also afforded her the opportunity to explore roles in feature films. She made her big-screen debut by replacing Julia Stiles in the remake of "The Fog" (2005), which she shot between the show's first and second seasons. The film hewed closely to the core plot of the Carpenter film - ghosts of shipwrecked pirates return to avenge themselves on the ancestors of those who caused their demise - but the new picture lacked the original's suspenseful atmosphere. It subsequently tanked at the box office, and Grace returned for her final eight episodes of "Lost."After departing "Lost," Grace found herself at the center of industry rumors about her participation in "X-Men: The Last Stand" (2006). The actress was widely considered to play the role of Kitty Pryde in the third film of the popular "X-Men" franchise, but as Grace later stated in interviews, she had no idea that she was up for the role, which eventually went to Ellen Page. She remained largely off-screen in 2006, but returned with a vengeance the following year with a single-episode guest shot on "Lost" as well as supporting roles in "Suburban Girl" and "The Jane Austen Book Club." In the former, a film adaptation of stories by novelist Melissa Bank, she was the best friend of New York editor Sarah Michelle Gellar, while the latter cast her as a member of the title organization whose high-risk lifestyle is turned into material for her partner's short stories. "Suburban Girl" saw little to no theatrical release, while the former performed modestly well on the arthouse circuit.The year 2008 saw Grace starring alongside Liam Neeson and Famke Janssen in "Taken," a French thriller about a former intelligence operative (Neeson) who uses his training to track down his daughter (Grace) after she is kidnapped. She was also top-billed in the British feature "Malice in Wonderland" (2009), an updated version of the Lewis Carroll story with a decidedly horrific bent.