When I wake up the third time I’m feeling a lot better. A surge of gratitude washes over me — the high the body throws up in relief that it hasn’t been annihilated by alcohol. There’s noise beyond my bedroom door and I can hear Lola running along the landing. I stand up and stretch then shuffle over to the window and look out. It’s afternoon. There’s a gentle knock on the door and Hannah’s there in tracksuit bottoms and one of her old vests that only just covers the bump.

“Mum wants to know if you’re hungry.” Her expression is completely neutral. It worries me.

“I could go another packet of crisps?” I say with a smile that is only half returned, before she tells me that I seriously need to brush my teeth.

“Use the green brush. There’s a towel and clothes for you as well.”

I take the hint and shower. After I’ve dried off, I pull on the shorts and faded Nike T-shirt she’s left out. Jay’s, but for me.

Hannah is waiting on the bed next to a tray of food: crisps, biscuits, cold pizza, slices of apple, a Mars ice cream and two cans. One Diet Coke, one lemonade. I don’t need to ask who the ice cream’s for as I sit down. That baby she’s brewing is made of the stuff.

“I’m so sorry. About last week.” I apologize from the pit of my very empty stomach before taking a slice of pizza. “And about last night.”

“You said some pretty scary shit,” is all she says in reply.

I don’t remember exactly what I said. I don’t remember much at all, only bits here and there, pieces of a puzzle that don’t give any indication of the whole.

“Like what?” I say, because it’s going to be the only way to find out. Not that I want to.

“You said you had no one.” She swallows, concentrating hard on finishing her ice cream. “That you killed your best friend, Chris.”

There’s a pause. I told her about Chris? I look down at the duvet cover, desperately trying to remember when I said that, wondering if I told her everything or nothing, or something hashed up and halfway in between.

“You said you wished you were dead.”

Hannah’s voice breaks and I look up to see that she’s crying. Grown-up tears that just run down her face.

I’ve never seen her look so sad.

“I’m so sorry, Hannah,” I say, shuffling closer and putting my arms around her. “I don’t mean that.”

“You did,” she says into my shoulder.

I think about lying to her, but how can I?

She squeezes into me so tightly I think she’s trying to climb into my soul. And I feel it coming, the choice between shutting her out and letting her in…

“Who’s Chris?” she asks.

I hold my breath and close my eyes. I think about a part of my life I’ve tried to shut away. But I let it out when I told Neville and now it’s here in this room, waiting to be shared with the person I most want to hide it from. I can’t afford to lose Hannah any more than she can afford to lose me, but if I don’t tell her the truth, then it’s over.

What the hell. Here goes.

HANNAH

And so I learn who Chris is — and what happened to him. It is the hardest thing I’ve ever had to hear, but I know it was harder for him to tell me.

It changes nothing. Aaron is still my favourite person in the whole world.

He is still my hero, even if he can’t see why.

AARON

Of the seminal moments in my life, Careers Day in the Autumn of Year 5 is my favourite. Everyone had to dress as whatever they wanted to be when they grew up. I had gone in a tweed jacket and a bow tie and when Miss Weston asked me what I wanted to be I told her that I wanted to be the Doctor.

“Shouldn’t you be wearing a lab coat and stethoscope like Paul?” She pointed to Paul Black, who was trying to strangle everyone with the stethoscope in question.

Before I could answer, a boy I didn’t know from the other class spoke up.

“Paul’s a doctor,” he explained, giving me a look of approval. “He wants to be the Doctor.”

“Who?”

“Exactly,” we said at the same time, relieved that she understood.

She didn’t. We were sent to the quiet table to reflect on why cheeking teachers was wrong.

“I’m Aaron Tyler,” I whispered across the table.

“Chris Lam.” Chris checked Miss Weston wasn’t watching and stretched over to shake my hand, blinking behind over-sized glasses. “Nice to meet you, Aaron.”

I shook his hand and grinned. “My friends call me Ty.”

Geekiness formed a firm foundation for friendship and when we studied for the entrance exams for Bart’s — St Bartholomew’s — it was Chris I studied with, hoping we’d pass or fail together. The day we heard that we’d both got in, Chris came round to my house to celebrate with lemonade and a batch of my dad’s legendary brownies. We’d just rolled out our latest architectural plans for the Death Star, holding the corners down with half-full glasses and empty plates when there was a knock on the back door and someone rushed in, waving a sheet of paper.

“I got in!”

My other best friend. The one I’d kept hidden from Chris. The one who knew more about Star Wars than George Lucas, who’d helped me paint all my D&D figures, who I’d known since nursery. Only problem was… she was a girl. Chris didn’t like girls.

“Penny — Chris.” I turned to Chris, who was sweating so much that his glasses had slid down to the tip of his nose. “Chris, this is Penny.”

“Hi!” Penny stuck out her hand and shook Chris’s so hard it nearly dislocated his shoulder.

It wasn’t exactly the start of something beautiful and I spent most of my first year at Bart’s a pawn in their battle for my best friendship, and the second trying to stop them from killing each other, until, eventually, after a thawing in Year 9, we hit puberty and Chris and Penny started getting on a lot better. So well, in fact, that they got distinctly friendly at the Year 10 Halloween disco and six months later, were still going strong when Chris went away to France for Easter.

That fortnight I enjoyed having Penny to myself. We’d hang out, watching DVDs and playing old-school RPG games on my computer, although I fully expected to lose her completely the second her boyfriend returned. It was a surprise when I was the one who received a text from him the day he got back, asking if I’d like to walk into town.

I met Chris at the end of his road.

“You sure you want to walk?” I asked, looking at the sky. Mum had told me to take a raincoat with me, but I’d ignored her.

“It’s not far.” Which was a lie, but he was acting strangely so I didn’t press the point. We’d been walking for about ten minutes, talking about homework neither of us had done, when we crossed the main road by Bart’s. The air was heavy and thunder rumbled somewhere miles away — a portent of doom if ever there was one — when Chris cut across what I was saying.

“I need to tell you something.” He opened his mouth a couple of times, as if practising forming the words. “I cheated on Penny.”

I stopped walking. The sky was growling and I thought I saw a little flash out of the corner of my eye. I didn’t know what to say.

Chris stopped a little way ahead of me. “Say something, Ty.”

“Why?” I ignored Chris’s shrug, not wanting to know the answer anyway. “How are you going to tell her?”

He rubbed the back of his neck. It’s a gesture I’d seen his dad use when he was about to say something no one wanted to hear. “I’m not sure about that.”

I narrowed my eyes. “How much did you cheat by, dude?”

Thunder in the silence. That was when I realized why he was acting like this: he’d slept with someone else.

“Got bored of waiting, did you?” My voice was harsh, but he deserved it. Penny had told him she wanted to wait until she was ready. When Chris had told me this, he’d said he didn’t mind and that he respected her for it.

Chris said nothing.

“So… what now? You popped your cherry on your holibobs and now you’ve confessed it’ll magically grow back?”

“Don’t be like this, Ty…” Lightning.

“Like what? What did you expect me to be like?”

“Just… don’t be a jerk.” Chris stepped closer. “I don’t want to hurt her… I care about her.”

That made me laugh. It came out mirthless and harsh against a rumble of thunder.

“If you really cared about Penny you wouldn’t be telling me this — you’d be telling her.” I thought of all the things she’d said about Chris in the last two weeks — the confidence with which she’d told me I’d know when I met the right girl… “If you don’t tell her, then I will.”

Chris looked up at me sharply, eyes narrowing behind his glasses as he absorbed the threat. “You’d sell me out, just like that?”

“Sell you out? I’ve known Penny since—”

“It’s not like she’ll come running to you because I’ve fucked up!”

There was a silence between us during which we both registered that he’d gone too far. Fat drops started to fall from the sky and I watched as the pavement turned dark with rain. The dim mustard light of the storm suited my mood. I couldn’t believe Chris had just said that.

“Look, I didn’t—” Chris started to say, reaching out to put a hand on my arm.

“Fuck off!” I said, slapping his hand away.

“Let’s find somewhere to talk.” He turned up the collar on his jacket and shrugged into it further as the rain spilled down onto us. “I’m getting soaked.”

“So?” I didn’t care about getting wet. I was too angry to care about a little rain. Or a lot of rain. My top was already sticking to me.

“Well, I’m not standing around here to get wet and ragged on by you,” Chris snapped and edged towards the kerb.

I grabbed his arm and pulled him back. “You’re not going anywhere until you face up to what you just said.”

He tried to shake me off, pulling away from me. The fact that he was trying to wriggle out of it infuriated me and I grabbed his other arm, twisting him to face me properly.

“Let me go!”

“Don’t be such a spineless twat, Chris!”

Angry, he shoved both hands hard into my chest, unbalancing me… but I still had hold of his jacket and I yanked him towards me, accidentally cracking the top of his head with my chin as I tried to stop myself from falling flat on my arse. It was the lamest fight ever to have occurred in the history of fisticuffs. We were more like two kittens tangled up in the same ball of wool until Chris clamped one hand around my shoulder and dug his thumb into the hollow above my collarbone, causing me to yelp as I let go.

Rain streamed down, plastering his hair to his head, rivulets cascading down his glasses. With one arm still rigid, holding me away from him, Chris wiped a sodden sleeve under his nose and checked for blood. There wasn’t any and, just like that, he seemed to tire of fighting and turned away to cross the road. Catching his sleeve, I tried to hold him back. I didn’t want us to leave it like this, not even for the length of time it would take to find somewhere dry to sit, but he must have thought I was still fighting him the way he whipped round and tried to shrug his jacket off. But that wasn’t what I wanted.

So I let go.

Chris wasn’t expecting me to do that. He was straining with all his weight, one foot resting on the edge of the kerb, one foot in the gutter streaming with rainwater.

So he slipped.

He twisted as he tried to regain his balance and keep from falling over. It was the wrong thing to do because he stumbled awkwardly and fell away from the pavement.

Into the road.

There’s a thousand little things that go into making one big thing happen. Wet tarmac, a car going a little too fast to catch the green light ahead, a boy who fell backwards when he should have fallen forwards, a boy who shouldn’t have let go of his friend’s sleeve when he did.

When you see something truly awful happen, you don’t process it at all — it’s only afterwards that details come to you. The only thing that registered with me was the noise: a sickening crack and thunk, both sharp and blunt, the sound of a body hitting a bonnet and breaking. It’s the noise I hear in my worst nightmares.

Chris was twisted all wrong on the ground and there was something darker than the rain pooling where his head rested on the road. I was terrified of finding out whether he was breathing, but I still walked out into the road and leaned forwards to check.