'Mum, where's Jess?'

'She's outside isn't she darling?'

'No, she's not.'

'I don't know then. She can't be far away, don't worry.'

'No, mum, I want to talk to her. Please.'

Bex couldn't really explain why she wanted to talk to her sister rather than her mum, but she had always been close to Jess and there was so much she needed to talk to her about. So much that she didn't even think her mum would understand. And she didn't want to cause her mum any more pain.

She saw the look of anguish on her mum's face and realised how much torment she's caused by running away. Her mum was too scared to let her out of her sight for even a few minutes.

Bex walked over to her mum and cupped her lines face in the small hands.

'I'll come back Mum, don't worry. I promise I won't ever leave you again.'

A tear trickled down Karen's cheek as she struggled to speak. In the end, she gave up and just nodded, forcing a small smile. Bex kissed her lightly on the forehead and left the room.

She didn't know her way around Waterloo Road at all and she didn't know where to start looking for her sister. The corridors were deserted and empty as every pupil was in lessons. Bex searched every corner of the school – she peered through every classroom window and looked in every set of toilets she could find. But there was no Jess.

A stab of pain went through Bex's heart. What if her sister was gone for good? Then guilt washed over her as she realised this was how her family must have felt for eighteen months.

A small object caught her eye outside and she saw a black outline huddled against a tree on the school field. Bex rushed out of the school doors and over to where her sister was sitting.

Jess' face was red and blotchy and her eyes were red and sore from crying. She looked as though she had been crying hard for hours, even though Bex knew it couldn't have been more than half an hour since she last saw her sister.

'Jess, I'm so sorry. Come here.' Bex moved to wrap her arms around her sister but Jess flinched and pulled away sharply.

'Sorry,' whispered Bex, but she knew nothing she could say was good enough.

Luckily for her, Jess didn't seem to have enough energy to move away and she sat there, shaking slightly. Bex didn't know if it was from crying or from the cold, but she took off her blazer and wrapped it around her sister anyway.

'Jess, look, I know nothing I can say will make what I did OK, but I am so so so sorry for what I did to you all. I was a selfish cow and I don't deserve any of you to forgive me or talk to me ever again. But I can't bear to see that I've upset you so much – I thought coming back would make everything better, but if it's making it worse then I'll leave.'

Jess opened her mouth but did not speak.

Bex tried again. 'Jess, I missed you so much. Did you hear what I told Mum?'

Jess nodded and started sobbing again. Bex reached out to touch her, but once again she pulled away and stood up.

Her eyes were blazing, and although she was still crying, Jess began screaming at her sister.

'You have no idea, do you? You have no idea of what we've been going through this past year. You think that coming back is going to make everything OK? Well it's not. Far from it. I heard what you said to Mum. You didn't come back because of us. You came back because you needed our charity. You're pregnant. You're just a pathetic slag, sleeping around because you don't know what else to do…'

Jess dissolved into fresh sobs, she was practically doubled over with them. She had stopped describing Bex, and begun describing herself. She realised how similar they were, except that Bex was forced into what she did, whereas Jess had done it because she liked the attention.

Her anger at her sister began to fade, as she realised how much she needed Bex too.

'I'm sorry, Bex,' she said, her voice barely a whisper.

And she sat down next to her big sister, buried her face in her chest and cried. She had always thought there was a limit to how many tears she had – after being dumped by boys in the past she always reached a point where she couldn't cry any more and things started to get better. But now, the tears wouldn't stop and she couldn't breathe from crying.

And Bex just held on to her. She was crying too – she hated seeing her sister in so much pain and realised there was more to this than just anger at her sister. She realised that she wasn't the only one who was going through a hard time – that her little sister had problems and difficulties too, and that they were going to have to face them together.

Finally, Jess found enough breath to talk to her sister.

'Bex, if I tell you something, do you promise not to tell Mum?'

'I promise, Jess.' It reminded Bex of all the times she'd covered for her sister when she was going to parties, or staying over at a boyfriend's house, and it made things feel more normal.

A few more tears rolled out of Jess' eyes, but they were barely distinguishable amongst the tears that were already on her face, and the smudged make-up and the swollen, red eyes.

'I- I- I slept with someone a lot older than me. And- I didn't realise that he knew Mum, but he does. And now he might lose his job because of me, and he just thinks of me as a stupid kid. And- I've slept with fourteen different people in the last two weeks, and I'm just a worthless slag, and I've probably caught loads of disgusting stuff and I'm just used goods and I'm not nearly as brave as you and–'

'Shush,' whispered Bex. 'It's OK, I'm here and I'm never going to leave you again. You're not a worthless slag, you're beautiful and strong, and we can talk about this properly when you're feeling better.

Bex rocked her baby sister in her arms. It had begun to rain a while ago, but neither sister had noticed, and they remained in each others' embrace for a long time.

'Jess,' whispered Bex after a while. 'Who is he, the person Mum knows?'

'It's Chris Mead, the deputy head. I didn't know who he was, I swear, I never would have gone near him if I'd realised…'

'It's okay, everything will be okay,' whispered Bex, comforting her sister like she had done so many times before. But she struggled to keep her voice level as her whole world crashed around her. Surely not. Not Chris Mead. Please. She prayed to God, even though she had never been religious. Her sister could have slept with anyone, just not Chris Mead. Please.