"Oh I'll cope," Jack said flippantly, shaking his hand a little absently. "I was once stuck for three weeks on an ice planet in nothing but a loin cloth. Good job I made good friends easily, that woolly mammoth kept me nice and warm." He was joking... mostly.

He smiled over at him, a little more genuine than the light heartedness of his words. "Why did you stay?" he asked softly. "You could have gone, it's not like you owe me anything."