The Temámir dwarf Birûk has been volunteered to help you discover what happened to Tatháta.
'You seek to learn where Tatháta the Sea-beast has gone? I have not seen her for quite some time. Are you certain she remains somewhere within Umbar-môkh? She is the Kinswoman of the Lower Ward, and you will usually see her striding through the streets, her two great hounds by her side.'
You tell Birûk that Tatháta was last seen within a hidden harbour beneath the city, and none have marked her passage in the days since.
'Well, I will ask around. But I should warn you. One thing is true beneath the city as it is in the streets above: there is a price for every question answered. If the Temámir of Mekab-kuphâr are to help you locate your missing woman, you should do what you can to help them in return: consult the notice board across the way to the south-west to see what we need done, and perhaps you will accomplish some of those tasks for us while I ask your questions for you. It is only fair, is it not? In Umbar-môkh it is very important for things to be fair.'
Birûk told you to examine the notice board to the south-west in Mekab-kuphâr to see how you can busy yourself while he seeks information concerning Tatháta's whereabouts.
Dealing with the wights at Sektakhâb, located to the west of Mekab-kuphâr, may encourage the Temámir to help you.
The notice board directed you to leave the things you recovered from Sektakhâb in the box back at Mekab-kuphâr.
Because the axe does not fit inside the collection box, you should just lean it against the wall by the notice board.