Once you zone into Sea Serpent Grotto go to (C-8) which will bring you to an area hidden on the map. You will pass through two Cracked Walls leading to a hidden room. In the very back of the room you will find the 'Shady Sconce'. Check it for a small cut-scene. (Make sure you check it twice to get CS with moogle.)
Then head to (J-11) and go through the Ornamented Door.
A Sahagin Key is required to open the Ornamented Door. This is a one-way door.
Oh, woe! Having exhausted all other options, your star-crossed moogle associate is forced to seek aid from the shadiest of scoundrels. You have an appointment with the underworld moneylender Riko Kupenreich at his office in Sea Serpent Grotto.
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