Kio did everything he could to make Karla comfortable at the bottom of the ladder. When she came out of the memory--he could tell because her eyelids fluttered and her breath changed speed--he didn't ask what she'd seen, though it was something he hadn't been present for and he badly wanted to know.
The Clockwork Raven
Citadel arc, chapter 7
Karla and Kio redouble their fight against the evil influence of the Inner Citadel...but the path saving Castle Nashido leads straight through the darkest memory of all.