It's that last comment, really, that makes her pause the most. Her brow furrows and she frowns deeply at him. A small ebb of doubt begins to creep into her.

"Doubting your own words would be one thing, but going so far as to want to kill Karkat? What could justify that?"

She felt off balance. She doesn't feel that was the direction to take with this conversation, but that had come out before she could even think.