Deliver Fellmoon's blackmail letter is a main quest in Might and Magic VIII: Day of the Destroyer. Arion Hunter's smugglers have the fastest boats in the area, so Elgar Fellmoon wants the Hero of Jadame to deliver a letter to him, "persuading" him to help the Merchant Guild.
Monsters[]
Ratman → Wererat → Greater wererat
Animalist → Shapeshifter → Lycanthrope
Bestial animalist → Bestial shapeshifter → Bestial lycanthrope
Walkthrough[]
Edgar Fellmoon can be found in the Merchant Guild house in Ravenshore. The Smuggler's Cove can be found in far west Ravenshore, along the coast.
At the back of the cove, there is a secret door leading to Arion's hideout. Turn left and walk up out of the water, going straight ahead when you get to the fork, and follow the passage back to a large room with two doors. Open the one straight ahead and go the door at the end of that room. Click on it to talk to Arion Hunter. The party must give him the letter, after which the monsters in the area will be friendly to the party.
Return to Edgar Fellmoon to receive your reward.