Salt hesitated until he saw Cardilini marching straight across the quadrangle grass towards him, creating a stir among the students. The teacher turned to where Salt was looking and took an involuntary step back.

‘Clear off,’ Cardilini barked at the teacher, who turned on his heel and smartly walked away. ‘Salt. Watch and listen closely and take every detail down in your notebook.’ Cardilini pushed Salt aside and stood examining the tree closely, ‘Now, observe that branch. There, that one. What do you see?’

Salt studied it closely for some time then turned back to Cardilini. ‘Sorry. I don’t see anything,’ he said.

Cardilini exhaled heavily. ‘What should we be looking for?’ he demanded.

Salt considered for a moment, but then shook his head in the negative.

‘Okay. You’re Edmund, right? Standing in the window. The open one with the curtains closed. Surveying your little kingdom, stuffed to the brim with how important you are, then bam half your head flies off and you get thrown back into the room to land flat on your back. Right?’

‘Yes, sir.’

‘Now. From where you were standing the bullet struck you, there,’ Cardilini pushed his right index finger onto Salt’s forehead, the force of it pushing Salt back, ‘then the bullet spread but kept on the same trajectory until it blew off the top of your skull. And its exit was roughly there.’ Cardilini pushed his other index finger on the rear of Salt’s skull. His fingers now held Salt’s head as if in a vice. ‘And you’re looking out the window, right? So what are we looking for down here?’ He took his fingers from Salt and stepped back. Salt turned to the window.

‘The shot was made from down here somewhere?’ Salt asked amazed.

‘Go to the top of the class. Now impress me,’ Cardilini said. Salt began to move around the area.

‘There are a lot of foot marks around this tree.’

‘Beside yours and mine?’ Cardilini asked.

‘Yes. And no one walks on the lawn.’

‘Passable.’

‘This tree could fit the angle of a bullet’s flight,’ Salt proposed, ‘But that would also be possible if the bullet came from across the river.’ They turned in that direction. From the top of the embankment they could see across the limestone wall to the river 200 yards away and beyond the river to low scrubland and open pasture. Cardilini dismissed the notion and turned his demanding gaze on Salt.

‘Are we looking for signs of the shot being fired from here?’ Salt asked.

‘Clever boy. Yes.’

Salt began examining the tree.

Cardilini suggested, ‘High possibility it was a .303 bullet that did the damage.’ Then asked, ‘Ever fire a .303 rifle, Salt?’

‘No, sir.’

‘Trust me then. The rebound pounds the stock of the rifle into your shoulder.’

‘Yes, sir, I’ve heard that.’

‘Right, it jumps back sharply. Now look at the branch.’

Salt stared closely at a branch chest high.

‘Okay. Now look at me,’ Cardilini said, ‘We don’t want to draw attention to that branch but a casual glance will show you where the bark’s bruised and slightly lifted. It tells me someone used that branch to anchor the shaft of the rifle. And there are two more curious marks on branches further up. And on the trunk, someone’s foot slipped when trying to climb the tree. You see these?’