The Tomb of Haggemoth

From the introduction:

“My old friend-

I hope that this letter finds you well, or at least in better condition than you were at our last meeting, for which I must again express my most heartfelt apologies. However, I did say that I would make it up to you someday, and I believe that time is at hand. I have stumbled upon a most amazing opportunity, which I can guarantee you will find profitable, and which is well suited to someone of your temperament and abilities. I dare say no more in this letter, but if you could meet me in the port of Ottoman Dock before the autumn equinox, I can assure you that you will not be disappointed.

- Your Servant, Zenatos”