Jekyll shares Lanyon's view that the two old friends must never meet again. As for himself, Jekyll says that he intends to lead a very secluded life from now on. However, he pleads with Utterson to believe in Jekyll's genuine friendship for him, but he asks Utterson to trust him to know what is best for all concerned. "I have to go my own dark way," Jekyll says, and it is a way that Utterson must not try and follow. He says further that he has brought a terrible punishment and a danger on himself; he never imagined that he could, or would, become "the chief of sinners," or that the earth contained such "sufferings and terrors"; he begs Utterson to respect his fervent wish for absolute privacy and solitude.
The lawyer's worst fears are confirmed. The old "dark influence" has returned and enveloped Jekyll; only a few weeks ago, it seemed impossible — Jekyll had seemed to be healthy and cheerful. Now, all that has changed, and what is more, Jekyll has condemned himself to a living hell. Utterson is tempted to diagnose the malady as simply madness, but because of Lanyon's frenzied condemnation of Dr. Jekyll and because of his ambiguity about his reasons for hating Jekyll so thoroughly, surely it is more than simple madness which now consumes Jekyll. There must be something else.
Less than three weeks later, Lanyon is dead. After the funeral, Utterson returns home and goes to his business office; there, by candlelight, he takes out a sealed envelope and studies it. Written on the outside of the envelope is: "PRIVATE: for the hands of G. J. Utterson Alone, and in case of his predecease to be destroyed unread." The emphasis on these last two words puzzles Utterson. Reluctantly, he decides to open the envelope. Within, there is another envelope, also sealed, with instructions "not to be opened till the death or disappearance of Dr. Henry Jekyll."
