Fleet had to grab the nearest pillar to steady himself. As he did, Zack began yelling to the crowd.

‘Hey! Up here!’

He shoved Richardson towards the edge of the platform, in the corner opposite Fleet. Richardson was more dishevelled than Fleet had ever seen him. His suit was ripped at the shoulder, and his tie knot was halfway around his neck. His cheeks were crimson, whether from anger or because the tie was throttling him, Fleet wasn’t able to tell.

‘Hey!’ Zack yelled again, and then he angled his mouth to Richardson’s ear. ‘There’s your audience, Callum. Why not give them a wave?’

Richardson bared his teeth in response, and Zack raised the knife and grabbed his tie, tugging at it as though he were a dog on a lead.

‘I said, wave.’

Richardson slowly raised his hand, and people down below began to point. Exactly as Zack had wanted, he and Richardson were centre stage. The fire in the chapel had been a distraction: a chance for Zack to get to Richardson without being caught. The fire in the southern wing of the school had been to drive everyone to the front of the building, so that Zack could parade Richardson before them, and finish what he’d started.

‘Zack,’ Fleet said, edging forward. ‘You don’t need to do this!’

‘Get back!’

Zack tightened his grip on Richardson’s tie, drawing him closer to the tip of the knife. Richardson’s eyes were fixed on the blade.

‘You have no idea what I need to do!’ said Zack. ‘You have no idea how long I’ve been made to wait!’

‘Twenty-two years,’ Fleet said. ‘I do know, Zack. I work with Nicky. I’m Detective Inspector Fleet. Rob. And I want to help you. But first you need to give me the knife.’

The mention of Nicky gave Zack pause.

‘Where is she, Zack? My friend, Nicky. What did you do to her?’

Zack’s jaw bulged as he bit down. ‘She shouldn’t have interfered. She shouldn’t have kept pressing. I didn’t want to hurt her! It was her fault for getting in the way!’

Fleet felt his stomach lurch, and this time it was nothing to do with his fear of heights.

There was a commotion below, and Fleet and Zack both turned. A fire crew had arrived on the scene, and the crowd was parting to let them through. The news teams had made it up the drive as well, and several had already begun filming. From being focused on the flames, however, the cameras were now pointing at the top of the clock tower, and the drone Fleet had spotted earlier was hovering level with the platform. Zack unpeeled his lips into a hate-filled grin.