She feels a flare of anger and stands, picking up her bag and striding out of her office. She walks quickly across campus, pace increasing, until she gets to Finn’s lab. She tries the handle but it’s locked, so she presses the bell, waiting for the answering buzz as the latch is released.

She pushes into the building.

The lab is strangely quiet. For the last few months it’s been a hive of activity. Computers whirring, the click of fingers on keys, lively discussion and debate. And Simon Sharp and Finn at the centre of it.

Sophie knew the two of them had their disagreements, but their friendship was built on mutual respect. ‘Debate is essential for growth,’ Finn once said to her. ‘Without challenge, how will we ever improve?’

Finn likes a good dispute. Smiling, he would listen to the person next to him grow more and more furious as he presented the counterargument, one point after another. Or he’d hold a finger up in the air as if to say, hold that thought, then walk away to do research and further reading. His PhD students loved him – even more so once Sharp joined the mix.

She spots Ian Calloway on the far side of the lab and walks over. He’s head down over a laptop, an array of electronics scattered around him; he looks up as he hears the sharp clatter of her heels on the tiled floor.

‘What was going on, Ian?’ she shouts.

His face hardens. ‘What are you talking about?’

‘With Finn. And Simon.’ He stares at her blankly. She grits her teeth. ‘Don’t tell me that everything was okay here, that there weren’t problems. I knew. I saw what it was doing to him.’

Ian’s eyes narrow. ‘You’d seen him drinking, had you?’ he challenges.

She stops, hands in fists. ‘No… I…’

‘So, you knew he was under pressure. Big fucking deal. Had you seen how he wasn’t eating? How he was working through the night, sleeping in his office?’

‘Why didn’t you stop him? Why didn’t you tell me?’ she pleads.

‘We knew how important this project was to him. It was everything,’ he stresses, and Sophie knows what he’s saying. More important than you. ‘But we didn’t know he was drinking,’ Ian continues, quieter. ‘And we didn’t know that he was so out of control he would kill Simon.’

‘He didn’t kill Simon!’

Ian gives her a patronising look. ‘Didn’t he?’ He flicks windows on his laptop and pulls something up. He points at it, turning to Sophie. ‘We found this on his computer.’

‘Why were you going through Finn’s stuff?’

‘After the police came and found all the alcohol, we wanted to know exactly what we were facing. So we went through his hard drive. Look.’