There reigned in Gaius's quarters a profound and deeply satisfying silence, and one that Merlin was hardly used to. Usually, when the physician was working there, the place would be filled with the crackling of flames, the hissing of chemicals, the chink of glasses; if he had a patient in, the air would be rent with their moans and groans; and even Merlin contributed to the noise, for he would clatter around inspecting whatever Gaius was doing or running errands or searching for interesting-looking books. A great contrast, then, to this atmosphere: he sat in the semi-darkness of the hibernating quarters and listened to his own heartbeat, tucked in a corner and gently trembling.

He felt exhausted. It was a strange sort of fatigue, this fatigue that afflicted his muscles and his brain, but which did not make him yawn or rub his eyes; it was as if he had spent the most immense effort. It was only as he began, slowly, to consider what had happened that he realised that he most likely had.

Magic. He had done magic, great and terrible magic. It had been instinctive. He didn't know what he had done. He only knew that the Lady Patricia had disappeared, and her own spell had been undone. He had felt his strength leave him – it was exhilaration and terror alone that had allowed him even to move, to run through the castle, before collapsing, spent, in a corner of the court physician's quarters.

Magic. He had done magic, in front of the entire castle. Yes, they had been asleep, but that did not stay his anxiety. What would happen when they awoke? Surely they would guess that something had happened! And they would notice that he was missing – and they would know that it was his fault. Magic was banned in Camelot. He knew that things happened to magicians – nobody had ever quite dared tell him what, but he knew that they must be terrible.

Thus he sat; and in this calming atmosphere, his breathing slowed, and his heart stopped racing; he might have fallen asleep where he sat, were it not for the footsteps in the corridor outside.

They were Gaius's: and as far as Merlin could tell, the physician was alone. Nevertheless he stood and took up a defensive stance, unconsciously, not knowing how his great-uncle would react. He waited with bated breath until he heard the footfalls reach the door: when it opened, he did not speak, merely stood there half in shadow, his eyes glinting.

Gaius's face did not betray what emotions he might be feeling. The physician looked down at Merlin, this poor frightened Merlin who looked ready to collapse into tears, and asked:

'Merlin, what happened?'

'Magic, I think,' Merlin murmured, and promptly collapsed into his arms.

'I didn't mean to do it,' Merlin protested, the moment he awoke.

Gaius was standing over him, looking deeply concerned, for the boy's face was extremely pale, and he had had a restless sleep.

'I didn't mean to do it,' Merlin said again. 'It didn't feel like me. The lady disappeared. She was going to do something to the king. What did people say? Are they going to come after me?'

As if spent by the effort of talking, he fell back onto his pillow. Gaius sat beside him on the bed, and clasped his hand.

'Merlin, don't worry. It's all right. Nobody knows what happened. They didn't notice that you had gone – they were too busy wondering where the Lady Patricia had gone.'

'Did nobody see me?' Merlin asked, almost in wonderment.

Gaius shook his head. Merlin thought for a long moment.

'Who was she? Why did she have magic?'

'I don't know.' Gaius hesitated. 'Merlin, you saw her... What did she do?'

And Merlin, in faltering terms, did his best to explain what he had seen and heard: the spell that had reached everyone but him, partly because he had covered his ears, but partly no doubt owing to his powers; the terrible silence that had fallen upon the hall, as everyone fell into a deep sleep; her advance towards the royal family, the dagger – then his intervention.

Gaius rubbed his temples. It had all happened so quickly, and there was still the disappearance of the Lady Patricia to explain away to the king. He wondered what the Lady Patricia had against the royal family – if indeed it had been the Lady Patricia. He realised, at length, that were it not for Merlin's intervention, the king, and perhaps those around him also, would be dead.

Leaving aside the political implications for the moment, the explanations that would have to be made, the lies that would have to be told, he looked down affectionately at his adopted son and said:

'You're quite the hero of the hour, Merlin.'

And all of a sudden a pinprick of colour spread into those pale cheeks: and Merlin smiled, vaguely, before rolling over and falling asleep again.

And Gaius sat, and fell into deep thought for a long while; then at last he went over to the shelf and pulled down a book. Once he had found the page he wanted, and read it over thoroughly, he bookmarked that page, tucked the volume under his arm and went to find the king.