Isabel Oliver Marcus

Isabel Oliver Marcus's breakthrough role as Allison on NBC's hit drama "This Is Us" is a classic Hollywood story of sudden success: In less than a week, she went from babysitting her brother to working alongside some of Hollywood's top stars. Although she had been living in Los Angeles for a year prior, Isabel and her mom were both visiting in Texas when the e-mail came through for an audition with NBC's Emmy-winning hit drama, "This Is Us." The role was very secretive, a recurring character known as "red-headed teen girl" and the audition designated that only those actors who were in Los Angeles and able to be in the casting room the next day should see the sides. Isabel wasn't even in Los Angeles, so her agents at Abrams Artists had to plead her case, ultimately convincing the casting team to let her submit a video read. She taped her audition on Thursday night, was "pinned" by the production on Friday, flew to Los Angeles alone on Saturday, had a "chemistry read" on Monday, and was