She knows he has the information she requested of him. She has likely already guessed the truth of what happened, but he bears the specific details, in all their wretched truth. Not telling her won’t return her daughters, but drawing this out any further will bring only more pain. Or so he supposes.

His horse drifts to the back of the line on the second day, a few steps behind the next-to-last person, just enough space for privacy, and waits for Guenievre to drift back as well.