Matsya asks you to help him talk to villagers in an attempt to sell them fish.
Requirements
This quest is available if you have completed the quest On Low Tide.
Starting the Quest
Talk to Matsya in Thavnair to begin the quest.
Speak with Matsya
Talk to Matsya to proceed. He will join you.
Speak with Mehrunnah
Go south to the quest icon in the minimap and talk to Mehrunnah. There will be an unskippable cutscene. The correct dialogue choices are "Greetings, friend. How fare you of late?" then "There's no place like home, but don't do anything dangerous, eh?", then "Speaking of meals, why not have some fresh fish today?"
Speak with Nashreen
Go north to the quest icon in the minimap and talk to Nashreen. There will be an unskippable cutscene. The correct dialogue choices are "What do you need so many amra for?" then "Are you sure you're actually hungry?" then "Do you like fish?"
Speak with Bhazahma
Go north to where the orange arrow is pointing in the minimap and talk to Bhazahma. There will be an unskippable cutscene. The correct dialogue choices are "You should take it easier—eat more slowly and savor your food." then "How do you intend to prepare?" then "Do we have anything suitable, Matsya?"
Accompany Matsya to the Pier
Go south to where the orange arrow is pointing in the minimap. Stand in the glowing spot and talk to Matsya to proceed. There will be a cutscene.
Speak with Thancred
Go north to the quest icon in the minimap and talk to Thancred to complete the quest.
Aether Current Quest
Completing the quest "A Fisherman's Friend" will unlock the blue quest Steppe Child in Thavnair. Completing "Steppe Child" will attune you to an Aether Current.
Next Main Scenario Quest
After you complete the quest, talk to Estinien to accept the next quest: House of Divinities.