"Goodbye, Michael Herondale," Puck sneered. He pulled Michael's head back to further stretch the skin of his throat.

Michael held his breath. So this was how he was to die – beaten down and vanquished. He swallowed, feeling the knife scrape against his skin as the throat muscles moved. He looked out at Mel. She stood motionless and displayed no emotion at all. It was like she had turned into a window shop dummy. He hated that he had not managed to save her.

He steeled himself for the final cut. He kept Mel in his sight. If he was to die, he wanted her to be the last thing he saw. He wanted to believe that somehow she was still in there, that the sight of his death might somehow reawaken her. He focused so hard on her and on this thought that he did not see the little shape that entered the doorway and lifted up a hand.

Something whizzed through the air and hit Puck. The Faerie gave a cry of surprise and pain and dropped the dagger from Michael's throat. The vines holding him also fell away as the one controlling them stopped doing so.

Michael quickly grabbed the dagger and spun around. Puck was holding his left arm and cursing loudly. A small throwing knife was lodged in his shoulder and dark blood was oozing from the wound. Michael did not stop to think but plunged the dagger into his heart. The Faerie dropped like a stone and the light disappeared from his eyes.

As Puck died, Michael saw Mel crumple onto the floor as well. "Mel!" he cried and rushed over to her.

But when he got to her, he had the biggest shock of his life. Henry Lightwood was standing next to her, throwing knives in hand. In fact, he was so shocked that he stopped in his tracks and stared, open mouthed.

"Hi Michael," Henry greeted, as though they were just in the Institute and bumped into each other in the hallway.

"Henry? What the hell are you doing here?" Michael shouted at him. "Do your parents know you're here?"

"Of course not," Henry answered indignantly. "I saw you rushing off in full battle gear and followed you. It was awesome."

"You little… idiot!" Michael sputtered. He was at a loss for words.

Henry helped him decide what to do next by looking at Mel and asking: "Is she ok?"

Michael shook off his shock and bent down to check on Mel. She was unconscious but breathing. "I guess so. She's alive, at least." He unbuttoned his gear and removed the shirt he wore underneath, draping it over Mel. "Keep her warm," he explained.

Henry had entered the storage room and was examining Puck's body. "Is he dead?" he asked.

"Yes," Michael answered. He went in and pulled the knife from Puck's shoulder. "You threw this? It was a good one."

Henry shrugged. "You taught me how," he said. He took the knife and replaced it in a sheath.

The enormity of what they had just done came crashing down on Michael. "Oh my god, we killed Puck. This is bad," he said. The Unseelie would not look favourably on this. Oberon might seek revenge for the killing of his favourite.

"No, it's not," Henry said. Michael looked quizzically at him. "After we researched the shadows thing the other day, I went and read up more on Unseelie. There was a section about Puck."

"About how malicious and tricky he is, I don't doubt," Michael quipped.

Henry shook his head. "No. It was… You know there's a story about how the Faeries came to be? Well, some of them?" he asked. "The story goes that they were once human. They were being persecuted – is that the word? Or is it prosecuted? – and so they went to live Underground. Eventually, they evolved into the Fae."

"Human changelings? Those are well documented," Michael agreed.

"Yeah, but there was this thing about Puck. There was a question about why he had so many names. Like, different folklore stories give him different names. But 'Puck' is always consistent. There's a theory," Henry's eyes gleamed excitedly at this point. "There's a theory that Puck isn't a name but a title."

"So?"

"So it means someone else can take up that title if the current Puck dies."

"I don't like the sound of that, Henry," Michael said. "What are you trying to say?"

Henry looked straight into Michael's eyes. "I'm going to stay here and become Puck."

Michael did not know a person could be hit by so many shocks in such a small space of time. "What? Absolutely not! You are not staying here. No way, Jose," he exclaimed, flailing his arms about to make his point. "Have you gone crazy, Henry? You don't choose to be a changeling!"

Henry's little face remained determined. "I won't be a changeling. Technically. Ayah always suspected there was a bit of Faerie in my blood mixed in with Shadowhunter. That's why I have the Sight."

"That's not the point!" Michael continued to rail at him. "By the Angel, Henry, if I have to knock you out and carry you back, I will. I'm not letting you become a Fae."

"It doesn't matter, Michael," Henry said. "I can't go back. They'll block my memories and send me back to the mundane world. This is best. At least there will still be a Puck, Oberon won't get angry and there won't be a war."

"How do you know Oberon won't retaliate? You think he can't tell one Puck from another?"

Henry pointed at the dead Puck. "That Puck is a different Puck from Shakespeare's time. Then it was Robin Goodfellow. Before that was someone called Jacky Rowan, and before him, Phouka. This guy is Robert Lavinker. They were different people. Now it'll be Henry Lightwood."

"Henry," Michael pleaded, squatting down to be on eye level with the boy. "Don't do this. Think of everyone who loves you back home. Think of Alec and Magnus. They'd be devastated."

"I'm sorry," Henry said. "I don't mean to hurt Dad and Ayah. Tell them that I love them. They were good to me."

"Are! Are good to you!" Michael objected. "And I won't tell them. You come back with me and tell them yourself!"

"Michael, I can't go back," Henry repeated. "This is the only way I can stay in the Shadow world. You could knock me out but then you can't carry me and Mel at the same time."

"Watch me," Michael said mutinously.

Henry looked around the room. A sack had burst open during the earlier fight and its contents spilled out. It was full of peaches. Henry picked one up and muttered quickly to himself: "Morning and evening, maids heard the goblins cry: 'Come buy our orchard fruits, come buy, come buy.'" Then, he put the peach in his mouth and bit down on it.

"No!" Michael shouted in horror. "No! Spit it out, Henry!"

But Henry shook his head again and swallowed the fruit. Michael grabbed him and shook him. But there was nothing to be done. The magic Under the Hill was such that those who ate the food of the Faerie realm would have to remain there.

"Thanks for everything you've done for me, Michael," Henry said. "Don't worry about me. I'll be fine. Go on, take Mel and go home."

"I'm going to come back for you," Michael said determinedly. "We'll find some way to get you back. Don't you dare get comfortable." He pressed his dagger into Henry's hands, the one he had used to kill Puck. "If any of the Fae try to kill you, you try to kill them right back, you hear? Even if it's Oberon himself."

Henry shrugged again. "Just get going."

With great reluctance, Michael forced himself from Henry's side and picked up Mel. He did not want to leave the boy here. But he could see no way of forcing him to return. It was true – if Henry could not be a Shadowhunter then there was nothing left for him in the world. How could he return to being a mundane after everything he had been through?

He took a long last look at the little boy – 11 years old, all long gangly limbs, messy hair and oversized sweater and jeans. Somehow in his heart, he felt rather than knew that this would be the last time he would see Henry as a little boy.

In his mind, he remembered Henry growing up. He remembered the first time he met Henry, then six years old and but acting a lot older after the violence he had experienced. Then as the boy grew, he remembered teaching the boy all the tricks of being a Shadowhunter, hanging out in Central Park, playing together in the Institute. Henry was as close to a little brother as Michael could imagine having. He stood there for a long time, imprinting Henry in his mind's eye.

"Ave atque vale, frater," Michael whispered.

"Go," Henry urged softly.

And Michael went.