He doesn't wear failure as well as he fears blood. It is the thought Seol takes away as Seo walks her to the entrance of the princess residence. He doesn't expect either Lord Oh or Oh An Ah would cave and give away the name of whoever is pulling the strings at their helm. It makes her furious at the helplessness they feel in the face of blatant treason that her lord father's sister comes up with - and how easily they get away with it, leaving the lower level supporters to bear the burden and get crushed beneath.
Seo has not yet forgiven her for running heedlessly into danger earlier and the tension of unsaid apologies hang between them heavily. He had left his furs with Bi, which Seo covers her with - in order to hide the state of her bloodied and torn garments. Seol inhales the mixed scents of horse and man, comforting in their own particular way.