Arthur seems fairly impassive, although his eyebrow quirks upwards as he gathers he's probably missing some important information to truly be able to find that joke unfunny.

"My father died," he says, blunt because he doesn't know any other way to be about it. That's a memory he retained to the nuance, of Uther in his arms, bleeding out. "I was his only son. Isn't that the way it normally works?"