He knows her well enough to see when she is hiding something. No matter the years or how many changes they underwent, she was still the one he was closest to. He would be able to read her face and understand what thoughts might run beneath. She was keeping this from him, likely to not disturb or frighten him. Or just as likely, she didn't want to reflect on the past and what happened.

He wouldn't press the issue for now, but eventually, he would want some answers.

"For a time?" That worried him. Did it mean that Arya wouldn't be there when he arrived? That was the one reunion that he had been looking forward to. Bran, certainly, but Arya...she was home to him. She would be the only semblance of normalcy that he had left.

"When did you leave?"