For what reason did Kettricken consult Fitz on their journey in the mountains and what did she ask him to do? What was his response to her request?

Kettricken consults with Fitz briefly as to the best route to take, and asks him why he does not use his Skill to reach Verity. Fitz explains he cannot because it would attract other Skill users to his location but the additional truth he does not share with her is that Fitz is afraid to use Skill as he will lose his mind in the process.