The Case of Charles Dexter Ward By H. P. LOVECRAFT - https://www.gutenberg.org/cache/epub/73547/pg73547-images.html

 To the Pawtuxet bungalow Charles transferred all the secrecy with which he had surrounded his attic realm, save that he now appeared to have two sharers of his mysteries; a villainous-looking Portuguese half-caste from the South Main Street Waterfront who acted as a servant, and a thin scholarly stranger with dark glasses and a stubbly full beard of dyed aspect whose status was evidently that of a colleague. 

And now that I am ready to speak, I must own with humiliation that no triumph such as I dreamed of can ever be mine. Instead of triumph I have found terror, and my talk with you will not be a boast of victory but a plea for help and advice in saving both myself and the world from a horror beyond all human conception or calculation. You recall what those Fenner letters said of the old raiding party at Pawtuxet. That must all be done again, and quickly. Upon us depends more than can be put into words—all civilisation, all natural law, perhaps even the fate of the solar system and the universe. I have brought to light a monstrous abnormality, but I did it for the sake of knowledge. Now for the sake of all life and nature you must help me thrust it back into the dark again.