"Oh, just shut up, Mum. I love him, ok, and there's nothing you can do about it."

"Isn't there? You're grounded, Bex, and I'm confiscating your laptop and mobile until you see sense. He's no good for you."

"Yeah? Well, try confiscating it from me when I'm not here." Bex stormed down the stairs and out of the house, slamming the door behind her.

Karen sighed and sat down on her daughter's bed. She'd come back later when she had time to cool down. She always did.

18 months later

The first day in a new job was never easy, and Karen Fisher's had exceeded all expectations in the way of bad. She'd led the first assembly in trainers, had to rethink her plans to close the cooler and nearly lost her deputy head. Then, of course, there was the matter of Ruth Kirby. The rebellious home-schooled girl hadn't been shy about protesting her disapproval of Waterloo Road, taking it to the extremes of running away.

That had touched too close to home for Karen, and it had taken all her strength to hold it together in front of Chris. She hadn't heard from her eldest daughter Bex in a year and a half, with no idea if she was alive or dead. It was the voiceless phone calls she occasionally received that kept her hope alive.

She wouldn't admit it to anyone, but she had spent so much credit simply calling Bex's phone to hear her voice on her answer machine that she had been forced to take up a job. Where better to work, then, than a school, where she could keep an eye on her two other children and simultaneously help others as well.

Jess and Harry had taken their sister's disappearance hard. There was only a year between Bex and Jess, and they had been close from childhood. Jess had rebelled against her parents, staying out all night and drinking, not that Karen let on that she knew about the alcohol. Harry had reacted in the opposite way, withdrawing and becoming reclusive. She'd moved the two to Waterloo Road in the hope that it would change both their behaviours.

The whole family had been affected, and Karen was determined to hold them together. It wasn't right to have favourite children, but it was Harry, as the baby of the family, that worried Karen the most. While Jess would voice her anger and frustration at her parents in the form of arguments, much in the same fashion as Bex, Harry would bottle things up and not speak to anyone for days if he was in a bad mood. Karen desperately wanted to connect with her son, but the risk of alienating her other daughter in the process restricted any movement she wanted to make.

So she was surprised, then, when Harry ventured into Bex's room in the middle of the night. Karen had struggled to sleep, so to avoid waking her husband, Charlie, she had headed into Bex's room to rest. Harry was normally a solid sleeper, so something had to be up if he was awake at three in the morning.

"Mum?" he whispered, sitting on the edge of the bed.

"What's up, darling?" Karen sat up and put an arm around him.

Harry held out his phone, displaying a video which was on pause. "Finn and Josh were talking about this earlier at school. I wanted to see it but then Mr Mead came in so Josh said he'd send it to me later. I watched it before I went to bed. It's horrible. It's Bex, Mum. I know it is. She's alive."

"Go on," Karen breathed. "Play it for me."

Reluctantly, Harry pressed play. A naked blonde girl was lying on a bed, pleasuring a man who could only be seen from the back. The man suddenly bucked up and urinated over the girl's body.

Karen's hand flew to her mouth, and she nearly retched. The girl was undeniably Bex, but what kind of life was she leading now? How had it come that her eldest daughter was featuring in degrading video stunts such as this? Or was it a stunt? The expression on Bex's face was one of horror and disgust, and Karen could never remember her daughter being a good actress.

At least Bex was alive, Karen reminded herself. That was the positive. Now she had a lead to go on, she would take Harry's phone to the police the next day. They might be able to trace Bex's location from the video, and they'd finally be reunited.

"Mum?" Harry whispered again. "Mum, I'm sorry. It's horrible. It's why I couldn't sleep. If I'd known it was Bex when they were talking about it in class I would have stopped them."

Karen hugged him tightly. "Harry. I'm proud of you, you know that?"

Harry smiled briefly. "Does that mean Bex might be coming home again?"

"Maybe. But we've a long way to go yet. I don't want you telling your dad or sister about this, alright? I don't want them getting false hope."

Harry nodded. "Alright."

"Now off you go to bed. We both need our sleep if we're going to find her."