Katharine Isabelle on her crazy side

Emily Perkins - who plays my sister - and I read scenes from Ginger Snaps, and we thought it was soft porn. But when we were given the whole script, we realised it was a feminist coming-of-age movie - funny, intelligent and scary. We totally fell in love with it.

I play Ginger, who is bitten by a werewolf on the night of her first period. My screen test was hilarious. I got worked up, booted the wall in the studio and put my foot through it. Everyone just cracked up.

Ginger is a slightly exaggerated version of my bad side. I'm not normally angry but, if I need to be, it comes flooding out in rage and I can't control it. I'm a double Scorpio, and I've a side that can be evil and dark and aggressive. I always get the bitch roles, never the girl next door. I'm better if I'm screaming or yelling or beating someone up.

I don't like horror films. The suspense makes a knot in my stomach - and I don't want to pay money to feel like I'm going to puke. Being in a horror film is easier.

Saying that, the scene where I get attacked was scary. We were in our 19th hour, the were-wolf kept attacking me - and it hurt. By the end I couldn't scream, my voice wouldn't go and I couldn't even lift my arms up. I've never felt that helpless in my whole life.