Way to unlock: Take the letter to the mailbox.
Quest giver: - (M3,37)
After you seal the Rift (M3,42e) you can enter a small cave with a corpse inside. On the corpse, there is a letter.
Collect it and deliver it to the mailbox next to one of the houses on the farm (M3,37a).
Rewards for completing the quest:
- Experience (little)
- 80 Influence points