I lost track of the days. They all blurred into one until the day everything changed. I was mindful of the vow I'd given William. I would not go to London until he told me I was ready. He knew about Rebecca. We'd talked for a long time on the night I'd signed the oath.

"You realise he might not even live there anymore," he said when I finished my story.

"If not, I'll track him down."

"You will fail to take him down if you don't get faster when I do this."

A kick aimed at my head. I caught it with the back of my hand just in time. "I saw that coming," I said.

"What about this?"

I looked down. There was a knife pressing lightly on my stomach. "I might not have seen that."

"Because your emotions get in the way. Tell me something, John. What did you do when she was taken?"

"I ran away from home. Went looking for her."

"Which lead to five years on the streets, correct?"

"Correct."

"You could have kept a roof over your head for five years while you looked. Did that not occur to you?"

"I couldn't stay home, not after that."

He looked at me closely for a moment before speaking. "You need to learn to turn your emotions off. Look only at the situation, nothing beyond it. Do not let your feelings get in the way of the job. If you'd done that back then, you would have followed him quietly, taken the number plate of the car, then tracked it down and maybe gotten her back."

"I was ten years old."

"And now you're fifteen and you're still letting me rile you. I can feel you getting angry already. Look at me. Do I ever look angry?"

"No," I admitted.

"Because I switch off my feelings. If you want any chance of getting her back. You need to do the same. Now go get changed, we're going to get some food."

They were waiting for us as soon as we stepped out of the door. I knew something was off but as usual, William was faster than me. As soon as we set foot outside, he shifted to the right, giving me a shove to the left. A quiet shot thudded into the wooden door behind us. "Move," William hissed, making a signal to me to take the left side.

I learned just how much the training had done for me that night. There were five of them. Only one came for me, the other four going for William. They clearly didn't factor me as a threat.

The man who came for me was dressed all in black, a balaclava over his face, a gun in his hand, silencer on the end. I saw him hiding in the bushes, the barrel of the gun pointed at me. I made as if I hadn't spotted him and walked on, jolting right just at the right moment. The shot went where he thought I'd be but he missed. I was already halfway to the bush.

He went to fire again and as he did so, I rolled forwards, catching his ankles and yanking, sending him to the ground. He tried to rise but I was already on him, grabbing his head and slamming it into the ground under him. Before he was able to react, I got the gun from his hand and pointed it at his chest, pulling the trigger while he went to grab it. His grip slackened on my wrist as the shot hit home.

I didn't pause to think about what I'd done. Instead, I got up and ran over to William. The four were working him hard but he had got some telling blows in. I pointed the gun but couldn't fire without risking hitting him. One of the men spotted me watching and turned, sprinting towards me. I fired twice and he went down.

William had hold of two of them and brought their heads crunching together. That left one man who looked between us before turning and sprinting away. William took the gun from me and pointed it, firing once. The man fell.

"I'm guessing Mr Sharp found me," I said, leaning on a wall and panting heavily.

William shook his head. "They came for me, not you, kid."

"How do you know?"

"Men like that are expensive. Five to get one fifteen year old is overkill. But they know not to come onto Juniper Place. They broke the rules. I think I'm going to have to have a talk with Carl."

"What should I do?"

"Well, we can't stay here."

"The police?"

"I have a contact who can straighten them out. The problem is they sent five here this time. Next time it'll be ten."

"Who sent them?"

"That's what I'm going to find out."

We got on the train together that night. I thought I was going back to London with William but when we pulled into York, he told me to get off. "I need you to stay here," he said. "Just in case anything happens to me. Book yourself in a hotel and wait for me."

"How will you know where I am?"

"Don't worry, I'll find you."

I didn't argue. I had learned not to. There was clearly a lot he wasn't telling me but I could only wait to find out what was going on. I took a room at a quiet guesthouse and waited. I couldn't get the image of the dead man out of my head. I'd killed someone. I was a murderer. The thought of it made me feel sick.

It was two days before William appeared, standing in the corner of the room when I woke up from my dream of Rebecca and the car driving away.

"You need to be more alert," he said as I sat up in the darkness. "If I'd wanted you dead, would you even have known it was happening?"

I lifted the duvet to reveal the gun pointed at him.

"You're getting better at this," he said with a smile before walking over to the armchair and sinking into it.

"What happened?" I asked, putting the gun down and sitting up in bed.

"Carl's dead."

"What? How?"

"I killed him."

I waited. He was clearly working out how to word things.

"Delaney went down to sign the building over to him. They ended up working together. Decided to make a fresh start as partners. Delaney persuaded him to tie up the loose ends first."

"You mean us?"

"Exactly. Carl talked to someone and paid for five of the best he could get to deal with us. Delaney called it restoring his honour like he was part of the mafia or something. I showed him the error of his ways."

"So now what do we do?"

"We stay here for now. Continue your training."

"But if Carl's dead, who are we working for?"

"You're working for me and I'm working for whoever can afford me."

"Doing what?"

"Doing what I used to do. Killing people."