I looked him straight in the eye. Had Tobias killed my girlfriend? Could he really have done such a horrible thing?

‘What is it?’ he asked. His look told me he didn’t appreciate being interrupted.

‘Why do you lock your door?’ I couldn’t think of anything else to say.

‘Don’t want Mum just barging in,’ he said. ‘You want something?’

I looked over his shoulder. His room was, if possible, even messier than mine.

‘Just wanted a word with you,’ I said, holding his gaze.

He let out an exaggerated sigh. ‘What about?’

I waited a moment, before I said: ‘The school show.’

Tobias tilted his head slightly as though trying to work out what I meant, how he should respond.

‘I thought you didn’t like school shows,’ I said.

Tobias just stared back at me. I half expected him to launch himself at me, but he stayed where he was, not saying a word. The expression in his eyes was back to weary and bored – as if it made no difference whatsoever if I was there or not. He looked like he might fall asleep at any moment.

‘Can I come in?’ I asked.

He thought about it for a few seconds, then opened the door wide with another sigh, as though being with his brother was the worst thing in the world. He slouched in behind me and sat down in his favourite chair. There were plates on the floor beside it. Glasses, bottles, a scrunched-up crisp bag. I counted four pairs of trousers on the floor. It looked like he’d just stepped out of them all.

‘You really should get some air in here,’ I said.

Tobias didn’t reply.

I didn’t know when it started – or why – or if we’d ever really been close, me and Tobias, but I couldn’t remember the last time we’d actually talked about something real and serious. Something other than kill streaks on Call of Duty or what kind of pizza we wanted to order. We’d never talked about Mum, for instance. Or Dad. Or Knut, the knucklehead who sometimes slept in our house.

I was still standing in the middle of the room. ‘Why did you go to the show, Tobias?’

He looked up at me. ‘Do I need a reason?’

‘Normally, no. This time, though, you do.’

‘I don’t need to explain myself to you.’

‘Yes, you do, because most people around this town think that I killed my ex-girlfriend, and one of the reasons for that might be the fact that they saw you there. They thought you were me. Børre Halvorsen had even seen you in one of the windows – the window the police think the murderer escaped through. I need to know what the fuck you were doing there, Tobias.’