I sat for at least another hour in front of my fire, drinking my wine, and considered the import of the evening. I have always been afraid for Henry, ever since our first clashes over his wild ideas. At times, I freely admit, I have even been afraid of him, or at least of what he might do with his attempts to create a medicine indistinguishable from witchcraft, especially after our last argument. I did not think then that he might have succeeded in any of his endeavours, for such things were surely not possible, but it brought him to mind, and set me to worrying over what might have alarmed Utterson so.

And who was this mysterious Mr Hyde?