My daughter is pale and drawn, her eyes red from exhaustion. She has spent days in semi-darkness, her curtains drawn against the sun. Her expression is blank, as if a world I don't know has embraced her, has taken her soul.
My 15-year-old is reading Stephenie Meyer's Twilight trilogy.
Girls reading Twilight are covered in bruises from falling down potholes and into lampposts. It's not only that they're lost in daydreams - they're reading while they're walking to school. Girls reading Twilight don't finish homework, wear odd shoes and forget to eat. They camp on the pavement for 34 hours in order to be first in the queue for the London premiere of Eclipse. They talk to each other in half-sentences, muttering about forests and muscles. They never, ever sleep.
In the end, in a superior, patronising kind of way, I started reading the first big fat book in the trilogy. Big mistake. I missed my stop on the bus to work. I am now covered in bruises, too. But I did start thinking about why teenage girls are falling in love with vampires.
First of all, it's not Count Dracula and fangs and garlic any more. There are no coffins or Transylvanian castles or dusty bats. Edward Cullen, the vampire hero of Twilight - with his marble chest glittering in the sunlight, his cool lips, his velvet voice - is physically breathtaking. Secondly, he is utterly and completely in love with our very ordinary heroine, Bella Swan. And finally, though intoxicated with the smell of Bella's blood, he won't give in. His love for her is so pure and monumental that he will fight his baser instincts.
That's it, then. Perfect boyfriend material. It's a shame he isn't human - but, hey, nobody's perfect.