‘Sandro in?’ I smiled.

‘Just left,’ she said sleepily.

‘Who are you?’ I put my good foot inside the door.

‘Marzia Colombi. Who are you?’

‘Renzo,’ I said. I use the name so often it comes out natural by now. ‘I’m a mate of Sandro’s. Mind if I come in?’

I walked in without waiting for a reply and shut the door behind me. She looked at me with a mixture of scorn and terror.

‘I’m not going to hurt you,’ I said. I pulled out my ID.

She looked back at my face and tried to smile. ‘Looks like you need a partner.’

‘I don’t do partners. What about you?’

‘How do you mean?’

‘Sandro.’

‘What about him?’

‘Where were you Wednesday night?’

She frowned. ‘Here.’

‘This where you live?’

She nodded.

‘With Sandro?’

‘Sure.’

‘And Wednesday you were here all evening?’

‘Sure.’

‘And Sandro?’

She frowned. ‘I don’t know.’

‘It’s time to remember.’

‘I…’ She was about to play ignorant again, but stopped herself. ‘What’s all this about?’

‘Did Sandro go out on Wednesday?’

She shrugged. ‘He said he wanted to get some gear in.’

‘What gear?’

‘You know,’ she said scornfully.

‘Where from?’

‘Lo Squarcione.’

‘Who’s that?’

‘The guy he normally gets it from.’

‘What’s it, exactly?’

‘Coke.’

‘And Lo Squarcione sells?’

‘Right.’

‘Did he come back with anything on Wednesday?’

She nodded.

‘And you know this character, Lo Squarcione?’

‘Sure.’

‘Where?’

‘He hangs out around the station. Always has.’

‘Dealing?’

‘Doing any business he can.’

I wasn’t sure what to believe. She looked too eager, like she was after something.

‘What does he look like?’

‘Who?’

‘Sandro’s dealer.’

She blinked. ‘Large scar from ear to nostril. That’s how he got his name I guess. He looks like the kind of kid who puts too much candy up his nose. You know, looks tense most of the time.’

I went through the flat room by room. Started emptying drawers, looking in cupboards, rifling through clothes. The girl was watching me as if she was thinking about calling for help, so I ripped the phone from its socket and threw her mobile off the balcony.

I went through the other rooms: the kitchen, the bedroom, the bathroom. There was nothing out of the ordinary. I went through the whole flat again, frustrated. It was a mess now, and the girl was whimpering. I didn’t even know what I was looking for, though I had a few hopes. If I could find his father’s credit card here I would be a lot happier that my theory was valid.

Nothing showed up. I pulled out my phone and called the Questura. I didn’t give my name, just told them to send men round to the address. I hung up before they could ask any more questions.

I grabbed her by her upper arm and held her against the wall. ‘This is a murder case, sister,’ I said. ‘That means people who kill and kill again. We’re going to the station. Let’s go and see who you see.’

She was shaking her head, staring at me with nervous eyes.

‘The carabinieri will be here in a few minutes,’ I said. ‘I’ve just called them. When they get here, they’ll arrest you and you’ll probably spend the next ten years inside.’

‘What for?’ she hissed. ‘What for? I haven’t done anything.’

‘No one ever does, do they?’

She was shaking now, not understanding my words properly, but understanding the sense somehow.

‘The only way out is with me. I’ve told you, I’m not going to hurt you if you help me, OK? You coming or staying?’

She started crying and I put a hand under her arm, took one last look around the flat and walked out, leaving the door ajar. She leaned heavily on me as we walked down the stairs.

I threw her in the passenger seat and sat down next to her. We saw the carabinieri arrive en masse and disappear up the staircase of the block.

I started up the engine. ‘You’re going to wait for a bus that never comes, you got it? You see Sandro’s dealer, you ask him for a cigarette. He’s the only one you talk to. You don’t approach anyone else, you with me? All you’re doing is asking for a cigarette.’

‘I’m not sure…’

‘He tries anything and I’ll put more holes in him than a scolapasta,’ I said, speeding up Via Trento towards the bridge. I hardly slowed at the roundabout. I screeched round to the right and on to the forecourt. ‘This may take hours,’ I said, ‘and it may not happen at all.’ I leaned across her and opened her door. ‘Just wait for that bus.’

She nodded and slammed the door shut. I parked up by the Toschi and walked back. From a few hundred metres away I could see the amassed lights of the station. Buses pulling in, heaving off. Cars dropping. Taxis hovering.

I crossed at the lights and sat on one of the stone walls under a tree. There were a couple of Moroccan men sitting there on a rug. From here I could see her. She was taking out a cigarette from her pockets and lighting it. ‘You’re supposed to ask for one,’ I said to myself, ‘not provide your own.’

She stood in the same place for a few minutes. She glanced around all the time, but it looked like she was searching for me, not her man’s man. I walked past her on the way to the ticket counter and told her to keep looking. I watched her from inside the station. Occasionally people would go up to her and ask something. She kissed a couple of people who recognised her. But she didn’t ever approach anyone.

I was just walking between one window and the next when I lost her. She must have seen me disappear for an instant and was suddenly gone. I went out there immediately but couldn’t spot her. There were trucks and buses parked everywhere. The Saturday morning crowds were already marching up Via Garibaldi. I ran away from the centre along the river but couldn’t see her.

There was no one who even looked like her. The pavements were busy with weekend shoppers coming in from all over the province now, and it was like looking for a needle in a haystack.

I saw a girl down a side street. It wasn’t Sandro’s squeeze, but it looked like someone about as desperate as me. She was hovering like someone needing a score and biting her fingers like she hadn’t eaten for weeks.

‘You want to earn some?’ I said to her.

She looked at me and assumed the obvious. ‘I don’t do that sort of stuff.’

She was a sorry sight. Dirty fingers and skin like a toddler’s knees. Her forearms were reddened by a rash, and her joints all jutted out as if the flesh had been sucked out of her. Her eyes looked tough and dead. They moved too fast, but never seemed focussed.

‘What happened to you, sweetheart?’ I asked bluntly.

‘How do you mean?’

‘Looks like you’ve got something nasty on your skin.’ I pointed my chin towards her forearms.

‘Yeah, well…’

‘Injecting?’

She threw her hands upwards in admission and I got a closer view of the needles’ damage. I looked at her face again: if she had washed her hair since the turn of the century she could have been quite cute.

‘How long have you been using?’

‘A few years.’ She shrugged.

‘Every day?’

‘Never miss one,’ she said bitterly.

‘Who are you buying from?’ I asked.

She didn’t say anything.

‘With respect,’ I said, ‘I’ve had tougher assignments than shadowing a junkie.’ She shrugged and I pulled out a note from my back pocket. She looked at it like a starving man might look at a plate of food.

‘Lo Squarcione, right?’

She looked at me scared now. ‘Who are you?’ She still hadn’t taken the note. She must have thought I was an undercover.

‘I’m a private,’ I explained.

She took the note and I told her to go find Lo Squarcione. I didn’t like paying for her habit, but I didn’t suppose it made any difference. I followed her round the back of the station and within minutes she had gone up to a thirty-something man and started talking. They disappeared round a corner for a minute, just enough time to get the camera out. Someone like Lo Squarcione doesn’t like to be away from the shop for too long.