Her answer confuses him, throws him even further off balance, if that were possible. He hesitates, eyebrows drawing together, wondering if it's a trick question.

"I -- dunno if anyone's ever told you, but it tends to hurt when you ram a sharp piece of steel into someone's flesh?" he replies slowly, an attempt at his old self, the dry quip a healthier Karkat would have answered with; it falls flat and awkward.

He shifts his weight from one foot to the other, unsure how to proceed with her so on guard. He wants more than anything else to approach her, pull her into his arms and tell her how he was so sure he wouldn't ever be able to come back, how sorry he is for leaving. Instead, he holds his silence and his place in the doorway. His hands curl and uncurl into fists; it's harder to keep eye contact, but he would sooner stab himself than look away from her now. He doesn't ever want to look away.