How does Stevenson present the character of Jekyll in the "incident of the letter"

Mr. Utterson goes immediately to Dr. Jekyll's residence and is admitted by Poole, who takes him out of the house and across a former garden to the "dissecting rooms." They enter, climb a flight of stairs, enter a door covered with imitation red felt and, at last, Utterson sees Dr. Jekyll, "looking deadly sick." He is alone and sitting beside a fireplace in a dim, dusty-windowed room. Utterson asks him if he has heard the news about Sir Danvers. Jekyll says that he heard the paperboys yelling about it earlier. Utterson is firm. He asks only one question of the doctor: Surely his old friend has not been "mad enough" to have hidden Hyde. Jekyll assures Utterson that he will never again set eyes on Hyde, that Hyde is "quite safe," and that he will never be heard of again. Utterson is concerned, however, and betrays his anxiety for his old friend Jekyll.