He could have brushed it off with an I'm fine (not strictly true, but it slid off the tongue so naturally after so much repetition) or a better now you're here (technically accurate, but no less of an evasion), but Marian was the one asking, and she deserved an honest answer.
"Better'n I was," Will said, after a second's hesitation. "Had some stuff to work through. Still got some stuff to work through," he amended, the corner of his mouth curling wryly. "But better. How're you?"