Having expected there to be some sort of meeting with leaders of the island, something that sounded more formal than what Thor described, Arthur was taken aback. He would simply find a place to live? That was odd. And new. He'd never truly known any home other than Camelot. He had been driven from it before, but always knew he would regain it; after all, it was his. This would take getting used to-- provided he did not actually find a way to leave.
Beasts, on the other hand, were the first familiar thing he had heard mention of in the last several minutes. That, he knew. That, he could handle.
What he did not care for quite so much was the way Thor was evidently trying to intimidate him. He was bigger and a few inches taller, and Arthur had no doubt as to his ability in a fight. Whilst he was no longer anticipating one, Arthur stood straight and met the other man's eyes as he spoke. He was not issuing a challenge; it was instinct. The son of Uther Pendragon and king of Camelot in his own right would hardly think to cower.
He watched Thor walk back toward Katherine and ended up moving closer to them, as well. He still maintained a slight distance, but had become aware of still being in the same spot he'd stopped when he found himself in this place, and wished to change that. He halted at Katherine's question, considering his words before answering.
"It was her decision, not mine." No matter that he had accepted the situation, it still pained him, and he tried as always not to let that show-- not completely successfully. "She decided that she wants me dead, and has killed many innocent people in her quest for that end. Even those she leaves alive suffer at her hand. It was not always that way; she used to be kind and loyal. But hatred took hold of her heart, and she became cold and selfish. She is also a powerful witch, which is a dangerous combination. She must be stopped."
The situation from which he had been pulled came back to him. "That's where I just was: in a battle with her forces, and that is why I have a hard time accepting I cannot return. While I have full faith that my knights can defeat her, I should be there to lead them."
And, when Guinevere heard the news... he could not think of the pain that would bring her. She, too, had his full faith, that she would go on and rule in his stead, yet he could not allow her to suffer that as long as he still drew breath. It was always possible that he would die in battle, and they both knew that. However, he was very much alive. "Also, I have a wife," he added quietly. "I should be back with her, as well." It was sharing too much, but there were too many reasons he did not belong on this island.