At least he's laughing, and not taking offense. Cassandra doesn't smile in return, but she's more tired than actually angry or disapproving.

"I am doing what must be done, and no more," she says. Perhaps not entirely accurate, but close enough that she believes it, anyway. "I am working because no one else can do this - because I must provide an example. And when the pain and exhaustion become too much, I will stop." She narrows her eyes at him. "Fighting until you collapse will only put you in greater danger, and create more work for the healers, in the end."