The Great Gatsby star Carey Mulligan was so unprepared for her April (13) meeting with the Queen of England, she needed to borrow an emergency safety pin to keep the hem of her dress up.

The actress attended the British Film Industry Reception at the royal's Windsor Castle home, but had no idea she'd actually get to meet Elizabeth Ii.

She explains, "I thought I would see the Queen from a mile away and take a photo on my phone or something, and then I arrived at Windsor Castle and someone said, 'Ms. Mulligan, would you follow us...' and I went into this room and there were just five people in there. And they said, 'You're all going to meet the Queen on your own'.

"I did my own hair... I just completely freaked out. And then this guy came up to me and he said, 'Ms, Mulligan, I just wanted to let you know the hem of your dress has fallen down. Would you like a safety pin?' And I was like, 'Yes, I need a safety pin!'

"If I met the Queen without a hem on my dress... my mother would behead me.

"He ran off and he got the safety pin and came back and he got down on the floor... and I was like, 'I need alcohol...'"

The booze failed to calm her nerves and she turned to actor/director Kenneth Branagh, who was also a castle guest, and asked him for a last-minute etiquette lesson.

She adds, "He's, like, practically related to them (royal family) and I said, 'Kenneth Branagh, what do I do?' and Kenneth Branagh taught me how to curtsy. It was a very brief lesson but he made me feel very comfortable."