Once you zone into Sea Serpent Grotto go to (C-8) which will bring you to an area hidden of 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.
If you zone after checking to the 'Shady Sconce' you must check it again before going to the 'Waterfall Basin'.
(Note: The use of Tractor did not require a re-visit to the 'Shady Sconce'.)(addition: Not only did I zone, but I logged and returned the next day after checking the ""Shady Scone"", and still got cutscene from ""Waterfall basin"")
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.
(See:Sahagin Key Quest. Only one party member requires the key to open the door.)
Once past the door, travel along the bridge path and inspect the 'Waterfall Basin' at (H-6) on the other side.
There is also a ??? located in this area, make sure you target the 'Waterfall Basin'.
Make sure to use some form of Sneak when you go past the Ornamented Door, as monsters will aggro at lvl75.
You do not need to go through the Cracked Wall in this area, so be careful not to run too far! If you do, you may need to go around again and get another key!
It's recommended that you bring some form of Warp as there are True Sound NMs on the way out from the area behind the Ornamented 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.
