Aubrey Lam Oi-wah's Hidden Track plays out like a modern-day metropolitan fairytale - and the princess she has placed at the middle of the piece is a Beijing Film School student who goes by the name of Popo. While scouting the mainland for a female lead, Lam and the film's producer came across the 20-year-old's tape and were struck by her 'sentiment', the director says. They travelled to Beijing to meet her in person, not sure what they were in for - whether she would be experienced or confident, ready or willing. In fact, she was terrified. 'While I was waiting for my audition I saw the producer in the hallway and I ran into the toilets,' says Popo. 'I was scared so I checked my makeup and tried to practise to become the character they wanted.' Whatever she did in there, it worked. And on meeting Popo, you can see what attracted the filmmakers. They wanted an innocent and fresh look. And that's exactly what they got. With her close-cropped hair, the diminutive, Shanghai-raised actress is a blend of Faye Wong and Bjork and it's that elf-like, wide-eyed quality that Lam draws on in Hidden Track. Like her character, Popo had never been to Hong Kong, which helped make her performance all the more natural, says Lam. Although she'd had a small role in a Taiwanese TV drama Red Apple Garden, Popo was untested in the wider world of feature film. She came into acting simply, she says, because it was easier than studying other things, and because it gave her more freedom. 'I was never a good student,' Popo says. 'I always preferred playing and sometimes that's what this is.' Popo is hoping Hidden Track brings her the kind of attention all young actors dream about. 'I had never really given it [starring in films] much thought,' she admits. 'I just try to be myself.'