Joan was angry.

Her face was white, but in each cheek was a vivid spray of red.

Disgust had been displaced by wrath, and her mood was clearly vengeful.
Sheldon laughed.
"It's nothing to be angry over," he said.

"You mustn't forget that he hacked off Kwaque's head, and that he ate one of his own comrades that ran away with him.

Besides, he was born to it.