In the Marvel films, British bombshell Peggy Carter needs no super powers to vanquish her enemies. But Hayley Atwell, the 37-year-old English actress who plays her in the most lucrative franchise ever made, certainly seems to possess something special.

When we meet, Atwell has just endured two and a half hours of emotional torment as the tragic heroine in a new West End production of Ibsen's Rosmersholm. Yet here she is signing autographs for fans at the stage door, wide-eyed and fresh as a sea breeze, looking as if she’s all set for a day’s work. Surely that’s a super power?

“I’ve never felt so energetic," she tells me as she leads me to her dressing room in the Duke of York’s Theatre. “I think it has a lot to do with having experienced adversity. You know, moments of failure in my career. But then, once you’ve been around the block you can let go of the person you think you’re supposed to be. My friends in their thirties and forties are much happier now because of that. I mean, there was a reckless thrill when you were younger of working s--- out and making horrendous mistakes, but now I feel I am driving my own life.”