I was asleep: to begin with.
The hour was just before midnight on Christmas Eve when a ferocious knocking woke me from my slumber. My first muddled thought, or rather hope, was that some specter or spirit stirred beneath the cramped rafters of my newly rented accommodations. Such a prospect aroused in me no little excitement — for though I am well versed with the actions and habits of apparitions, ghosts, and hauntings of all sorts, I have always had to seek out such extraordinary creatures in situ, as it were, and their attentions had never been initially directed toward me. I thought immediately of the incident of the Knocking Well, when I helped lay to rest the unquiet spirit of a lost child in Somerset, and so I leapt to my feet and pulled on my dressing gown to begin my investigation. I followed the sound of knocking, now ever more ferocious, through the corridor and down the narrow stairs.
Alas, it soon became clear the knocking was of an entirely ordinary sort, attributable to some visitor pounding upon my front door — though the lateness of the hour did suggest some manner of emergency or alarm. When I opened the door, a wild-eyed creature, with a ghostly white aura about his head and loose robes that flapped wildly in the wintry winds, forced his way inside, and I reconsidered my assumption that he was a mortal man. I had certainly never encountered an apparition polite enough to knock — however vigorously — before entering, and when he spoke, I was crushed by the mundane quality of his voice, which possessed none of the eerie harmonics I associated with those few spectral beings who deigned to speak.
“Mr. Hodgson, I presume? I have immediate need of your services, man!”
He was a frightened old man, and I was acquainted with such; I had met the terrified, the dread-filled, and the desperate over and over during my researches into the occult.