I'm not going to pretend I know why or how— [ Caster is the last one to be lying, even if he's absolutely okay with omitting information for ~~reasons~~ honesty is his preferred approach. ] But I'm familiar with similar phenomena. They were always aberration from the main branch of my world's history though. So my view is already skewed.

[ Given the runes and culture, and even language, reminding him of his homeland of old? He's not denouncing a possibility that its some weird alternate future of Ireland or whatever, as unlikely as it is ]