The Missing Manifest

The item is located north of Nagrand under the sea at 59.35, 1.36.
There are four mobs guarding it ([npc=95095], [npc=95097], [npc=95098], [npc=95100]).
It is turned into [npc=83888] who is next to [npc=83867] in the black market auction house in the Ring of Blood.

Upon completing the quest [npc=94829] joins your garrison (behind the mailbox outside the town hall Alliance side). She allows you to see the current BMAH items, but doesn't accept bids.

https://twitter.com/WarcraftDevs/status/624378815805030400

[npc=94829] will become a resident of your garrison upon completing The Missing Manifest. Which comes from [item=127989] rewarded from the shipyard mission [mission=647].

She is located directly outside of your main garrison building next to the mailbox.

Currently, she is only able to show you what is available on the BMAH. Her interface does not allow you to bid on any of the items yet. I am unsure if this is intended or just a bug.

Easter Egg:

The 4 mobs which are protecting the quest item are a reference to Payday Characters

WoW - Payday:

Ghains - Chains
Vulf - Wolf
Huxto - Hoxton
Dollos - Dallas