She hikes up Marlborough Hill rehearsing an ideal script of the upcoming conversation in her head. It helps calm her nerves. The truth is she’s a little afraid of Tash Tillotson. At the library she’d got the feeling that she was standing beside a death star or a black hole, something vast and scary that was in the process of collapsing in on itself. And then there was the email or, rather, both emails. What did Tash mean by saying she bet Nevis did know? What did Nevis supposedly know? And why would Tash imagine that someone could be next? Why would anyone be next? The girl was a mystery and mysteries of any kind set Nevis’s teeth on edge.

Three-quarters of the way up the hill she takes a right and walks along a street of small stone houses to a block of flats. She makes her way through a riot of weeds to the main entranceway and presses the top bell. Moments after ringing it she hears a door swinging open upstairs. Then the hall light comes on and through the panelled glass of the front door a shadowy figure makes its way towards her. The door opens and in front of her stands Tash, smelling of weed and looking slightly flustered, her long brown hair tied in an unruly bun on the top of her head, looking as if she hasn’t slept in days or, conceivably, weeks.

‘I thought you were someone else or I wouldn’t have come down,’ Tash says, scanning the street this way and that.

‘Do you mind if I come in?’

Hands on hips, eyeroll: ‘If it’s about those emails, I was drunk, OK?’ A lip-suck followed by a repentant sigh. ‘I shouldn’t have sent them, sorry.’

‘I’m trying to understand about Satnam. Why she did what she did.’

‘What difference does it make?’

‘Maybe none. But I like to be able to understand things.’

Tash’s chest heaves but she stands aside for Nevis and leads her into a damp hallway and up the stairs to a small, messy flat with sad walls, undecorated except for a few band posters and a couple of incongruous landscape prints. The kitchen is a few worn cupboards, an old cooker and a cheap, half-sized fridge along one wall of the living room. The air smells of weed and bottled pasta sauce. Three empty cans of cheap lager on the coffee table in the living room suggest that others were here a while ago, but they are alone now. Music is playing on a Bluetooth speaker, something grimy. Not Nevis’s bag.

Tash gestures to a chair and says, ‘Want a beer? I’m having one.’ Nevis sits and, blinking at the mess before her, says, ‘Coffee, if you have it?’