The quotes that inspired this little piece. (extracts from City of Bones)

"He didn't cure Alec; that was Magnus Bane."

I don't know what we would have done if Magnus hadn't showed up and magicked Alec back to health.

"It was so awesome. He showed up and ordered everyone out of the room and shut the door. Blue and red sparks kept exploding out into the hallway from underneath the floor."

"I don't remember any of it," said Alec.

"Then he sat by Alec's bed all night and into the morning to make sure he woke up okay," Isabelle added.

"I don't remember that, either," Alec added hastily.

Isabelle's red lips curved into a smile. "I wonder how Magnus knew to come? I asked him, but he wouldn't say."

Clary thought of the folded paper Hodge had thrown into the fire after Valentine had gone. He was a strange man, she thought, who'd taken the time to do what he could to save Alec even while betraying everyone—and everything—he'd ever cared about. "I don't know," she said.

Magnus was lazing on his sofa, stroking Chairman's fur as he sat curled on his lap. He was contemplating the way he could change the decorum of his loft, when his musing were interrupted by a fire message popping out of thin air.

Chairman hissed, standing on all fours, claws digging in Magnus's leg.

"It's quite all right, Chairman. A little message. You have to get used to such things." He petted the kitten, picking the piece of paper from from next to him where it'd fallen.

The Institute of New York requires the assistance of the High Warlock of Brooklyn. One of our Shadowhunters is badly injured after a fight with a Greater Demon.

His sharp intake of breath made the cat cock his little head to the side.

Magnus idly wondered which of the Nepilim idiots had been stupid enough to confront a Greater Demon. They seemed the attract trouble like a magnet, lately.

As he rushed to get dressed, fear gripped him as a new thought entered his mind. Not tall, dark and handsome. Not Alexander.

Magnus shook his head to clear it of unwanted thoughts.

No. Alexander was smarter than that.

He created a Portal that took him in front of the Institute. He rang the bell, waiting for someone to open the door.

A disheveled Isabelle greeted him in a tight voice, not expecting him there. Magnus didn't pause to ask about who'd sent the message, only brushed past her, hurrying to the infirmary.

"Which one of you upset a Greater Demon?" Magnus asked in the elevator cage that took them to the upper floor.

"I guess Clary, but we all went with her. Her neighbor wasn't her neighbor. Abbadon had taken possession of her body. We didn't realize he'd hurt Alec until it was too late. He was so brave. He managed to send him away, but now...he'd badly hurt. The Brothers couldn't help."

Abbadon?

Alec hurt?

The Silent Brother not able to help?

"You lot are disrupting my peace with your mischief." It was the only thing he could say that distracted him from imagining Alec hurt.

At the infirmary, Magnus sent the useless Brothers out of the room, closing the door in Isabelle's face.

Seeing Alexander so pale and the advanced damage the poison had done, he set to work as quick as possible. He didn't pause to look at Alec's face, because it would shatter him, seeing the beautiful Nephilim in such a state.

After mixing the ingredients he'd brought from home, Magnus uncovered Alec's body with a wave of hand, before applying the lotion he'd created. Next, he used his power to take the pain away, because he could tell his patient was coming around and the cream would burn his skin where it came in contact with his injuries.

"Shh. You'll be just fine, darling." Magnus touched the side of Alec's face, twisted in pain. "I'll take care of you."

Once he'd done everything in his power to heal Alec, Magnus went out to announce Isabelle that her brother was going to make it. She threw herself at him, thanking him profusely.

"You can come see him." Magnus walked her to Alec's bed. He took a seat by Alec's side, taking one of his hands between his.

Isabelle watched the gesture with surprise, but her eyes moved to Alec's face. "He looks much better."

"He might be in some pain when he wakes up, but I will make a potion for him to take. In the meantime, I'll take all his pain away this way." Magnus squeezed Alec's hand. "If you're tired, you can go to bed. I'll stay with him."

"Are you sure? You don't have to stay. I can take care of him," Isabelle said through a yawn.

"I'm not leaving until I know he's better. Go to sleep, Isabelle."

I'd really love to see Magnus healing Alec, and staying by his bed all night.