Alongside the wig, Seyfried also had to contend with six-inch heels - all the while in full gun-toting, car-chasing action movie mode.

"Louis Vuitton boots and YSL pumps… oh god, It was awful," she recalls. "On the second day I was running and I didn’t have the stunt heels on yet and I fell so bad … luckily I was holding onto Justin’s hand so he had to swing me down without hitting my head – really funny but really scary at the same time. I literally flew underneath him, he landed on top of me like this (gestures). It was just because I was running SO fast, the fastest I could ever possibly run with heels bigger than these on – god, terrifying."

Despite the running in heels challenge, Seyfried clearly enjoyed her stint as an action hero and "being one of the dudes," as she puts it.

"I think I even hit my head at one of the crash scenes when Raymond Leon’s (the token bad guy) car crashes into us near the end and I whacked it – and I felt like a dude… I loved it. They didn’t treat me any different because I was a female," she says.

But even with all the excitement, Seyfried's not willing to embrace action full-time, at least for now: "I just don't think I’ll ever be like Angelina Jolie in that respect because it’s just so full-on, you get really tired really easily."

Interview: Amanda Seyfried