Below him, a strange plucking sound, like a man endlessly tuning a lute. He went down stairs and found Hooke sitting there with a few inches of quill sticking out of his ear, plucking a string stretched over a wooden box. It was far from the strangest thing Hooke had ever done, so Daniel went to work for a time, trying to dissolve Wilkins's bladder-gravel in various potions. Hooke continued plucking and humming. Finally Daniel went over to investigate.