William was really not in the mood for further pleasantries at the moment, but they had an audience (why did he seem to end up so often having made a scene in front of students?) and he had rather rudely interrupted Bob's lunch meeting. The fact that Bob's proximity alert charm would have interrupted it a moment later was besides the point.
"My apologies for the disruption, Healer Bryar," he said quietly. "Please let me know if I can be of any help."
He disappeared before Bob could make an attempt to detain him, slipping back to the safety of the Goblin Poetry section, which was nearly always empty. He picked a book at random, read three sentences, and made a face at the reminder of why this particular section was frequently abandoned.