From the look on Doctor Jekyll's face, I guessed that he already knew who his late-night visitor was, but I continued with my duty. 'It is Mister Utterson, sir. He wishes to see you if you are available.'

He paused for a moment, and I felt that he would perhaps prove my guess wrong and that he would see his old friend after all, but then he shook his head. 'No, Poole. Tell him that I'm out.'

'Should I give him your dinner invitation, sir? Save a trip in the morning, it would.'

'No, Poole. Say nothing. It would be better delivered separately. Maybe not even tomorrow, but on Wednesday or Thursday. For now, tell him I am not in and send him on his way. If he asks about my colleague Mister Hyde, tell him the truth but venture nothing.'