AGE: 29. PROVENANCE: London, England, HOUSE SEATS: "I was taken to the theater quite a lot as a kid, and I remember seeing Vanessa Redgrave in The Cherry Orchard and thinking, I want to do that, get in someone else's shoes and explore the world in that way." RISKY BUSINESS: Bucking tradition, she chose to make her professional debut instead of attending drama school. "I had to gamble. I could've done three plays in six months and never worked again." But the work hasn't stopped. "I am very lucky." THE SPARE HEIR: Next month, Kirby returns to Netflix as Princess Margaret in the award-winning series The Crown. "We really delve into the darkness of an identity pulled in two different directions, and how that affects somebody with as much life force as she had." NEW MISSION: Next year, she trades palace scandal for international espionage with Tom Cruise in Mission: Impossible 6. "I met him at the studio; we had a chat; he shook my hand and said, 'Welcome to the family.' I hadn't even seen a script." DREAM PART: "There are so many incredible stage roles for women. I really want to play Hedda Gabler—it's a bit cliche but a rite of passage." GOLDEN AGE: "I feel there is a real turn to female directors and writers, and their stories. I want to be part of that change."