The frown that graced Opal Koboi's face as she stalked away from her father's study would have informed even the most unobservant onlooker that she was not a happy pixie. Were they also to note her clenched fists and the grinding of her teeth, they might go as far as to call her furious. And they would be right.

Ferrall had just finished giving her another one of this talks. It had been the same things as usual - science isn't for you, marriage is your best option, blah blah blah. And he'd even had the nerve to suggest that she was big-headed! Well, Opal was sick of it. She wouldn't put up with it any more.

"It's only because I'm a girl," she growled as she turned a corner. "They don't care if all of my talent goes to waste. They'd rather preserve their fragile chauvinistic egos." Opal's father was not the only one who had tried to hold her back - she was referring also to a significant portion of the male staff at her college.

Perhaps it was the blunt put-downs which had first begun to warp Opal's mind. Told not to flaunt her abilities, she had, of course, done so. And when her parents pointed out her personality flaws in an attempt to help her reform, the highlighted traits had worsened. The more headstrong they said she was, the more headstrong she became.

"I'll show them! I'll show them all," she hissed, storming past a maid and heaving open the front door. "I'll be the best." She dashed down the majestic stairs, feet angrily slapping the marble. "Then everyone will have to sit up and listen."

She halted suddenly, a few metres from the bottom step. Her breath was coming fast and heavy. "And then nobody, nobody will ever tell me what to do again." She twisted her head slightly so that the house was just on the edge of her field of vision. Looking out of one of the windows was her father, a tall, concerned figure, and an example of everything she had come to hate. "Nobody!" she screamed, face flushed.

And as their eyes locked a second before she turned to leave, Ferrall began to wonder if he had misjudged his daughter. She would succeed. He realised that now was the time to start fearing not only for himself, but for the whole Underground.