He hesitated on the threshold, so powerful was the stench.

That hesitation killed him. There was a thunderous noise from the neighbouring garden, and a brief flash of light. In the second before Leeman crashed to the ground I saw, by the light of the lamp, that he had lost half his head. We stood there, shocked for a few seconds, then Nicholas threw me to the ground, just as there was a second flash and a bang, and the smell of smoke. Glancing aside I saw that Barak had also thrown himself down. He kicked over the lamp he had been holding and it went out, leaving us in almost total darkness. I smelled gunpowder in the air.

‘Quick!’ Barak whispered. ‘Back inside. Before he has time to reload. Nick, you know the way in the dark!’

Nicholas scrambled to his feet and, with his long body bent over, made for the back of the building, which was visible only as a slightly deeper darkness. Barak followed, and then I, biting my lip as a muscle in my back went. There was another bang, another flash, and something hit the wall ahead of us. Then I heard the door creak open, and Nicholas pushed me unceremoniously inside. Barak followed, kicking the door shut behind him. Outside dogs had begun to bark and someone in a neighbouring house, woken by the noise, shouted, ‘Hey! What’s going on?’

Nicholas led us to the front of the house and the shelter of the stairs. We stood in the darkness, breathing hard. I said, ‘What in hell – ?’

‘A gun,’ he answered. ‘An arquebus. I’ve seen them used in hunting. They’re deadly, but take an age to reload. Leeman – ?’

‘Dead,’ Barak answered flatly. ‘It took his head off. So we were followed here, by someone who brought an arquebus. Clever idea to post the assassin in next door’s garden; we were bound to come out to the jakes sooner or later. Great way of killing a person from a distance. There may be more of them out the front.’ He walked cautiously to the front door and peered through the keyhole. ‘Can’t see anyone. I’d guess it was Leeman they were after. To stop him talking to us.’

‘At least they failed there,’ Nicholas said defiantly.

‘Come on, back upstairs. Thank God we kept the window of your room shuttered.’

We returned to Nicholas’s room. ‘Sir,’ he said urgently, ‘it would be dangerous for Jack to go out now. There may be more of them waiting in the streets.’

Barak shook his head. ‘I should think they’ve run, now we’re safe indoors. But you’re right. We should all wait here till Lord Parr’s men come from Whitehall.’

‘But why didn’t they follow us in when we first arrived?’ Nicholas asked me.

‘Perhaps because they thought the house might be full of students, and they’d have a fight on their hands.’