As the teacher droned on, all I could think about was seeing Yugi later. Finally, the bell rang. I hurried out of the classroom and down the hall. I need to get home and get ready. But I was stopped by a voice from behind, "Tea, Tea!" Not again. It was Serenity.

"What now?" I snapped, turning to face her. She had a habit of bugging me. She seemed lost for words.

"Go on," I said, impatiently, looking at my watch.

"I was just wondering what you're doing tonight," she stammered. "Maybe we could do something?"

Irritation washed over me. "Serenity, you know I'm seeing Yugi later. I don't have time for this!" I barked. I was beginning to think she was jealous that I had a boyfriend. She always wanted to spend time with me, even when she knew I had plans.

Five days ago it was: "Tea, do you want to catch a film? Maybe I could stay over afterwards?" The week before: "Can I come round? I need help with my homework." Both times, she knew I was seeing Yugi. OK, she was my best mate, but she was starting to feel like my stalker.

And as I rushed to the bus stop, I heard footsteps behind me. It was Serenity again! "Tea," she pleaded. "Can I come back to yours - just for a while?" I needed to fix my hair and make-up - I didn't want her around.

"I'm sorry," I said, barging past her to board the bus, "Maybe some other time, yeah?"

Walking home from Yugi's house later, I should have felt happy. But I couldn't shake the guilty feeling inside. I'd been really hard on Serenity.

The next day, I woke up late. I reached for my moby to text Serenity. I wanted to meet her before registration to apologise. But as I pressed 'send', Mum entered my room. "I think you should sit down," she said softly. "Darling, something terrible has happened to Serenity."

Mum explained that Serenity's brother, Joey, had found her that morning, an empty bottle of pills by her side. He'd felt her pulse: nothing. Suddenly my throat tightened as tears streamed down my face.

"Why did she do it?" I cried, as Mum tried to comfort me. She was my best friend, but I'd been such a bitch. Overwhelmed with guilt, I told Mum I need to be alone. But as she shut the door, I switched on my computer and took a piece of paper out of my top drawer. It was the URL for Serenity's secret blog. We used to read each other's diaries all the time, but I'd been so busy with Yugi I hadn't logged on to hers for weeks. Hands shaking, I typed in the address and clicked on her final entry:

Monday 14 October, 2006
"I begged her. I chased her down the corridor like a lunatic, praying she'd cancel with Yugi. Praying she'd save me from another night of torture. Tonight he used a rolling pin. The pain was unbearable.

"She pushed me out of the way earlier. But I'd rather a million pushes from her than one more beating from Dad. The loneliness hurts more than the bruises. I can't take either any more..."

I logged off, unable to breathe. Why had I been so selfish? I had let my best friend down. And there was nothing I could do to change it.