"Thalia and Melpomene" is the final quest in Genshin Impact in the questline "Search in the Algae Sea". During this mission, you will need to find the last, fourth seal and continue the story of Narzissenkreuz Ordo.

How to Get the "Thalia and Melpomene" Quest

The quest will automatically appear in your quest log after completing the previous mission – "Cupid's Lover". This is the final puzzle you need to solve to continue the storyline quest and decipher the riddle of Narzissenkreuz Ordo.

Thalia and Melpomene: Walkthrough

Head to the Last Seal

The destination is the waters of the Morte Region. Dive down to the marker and swim to the temple. Once inside, go ashore and proceed forward until you encounter a barrier.

Talk to Everyone

A short cutscene will start in which the group solves another puzzle. The correct answer is "Oceanid." After solving it, all the characters will be able to pass through the barrier.

Decipher the Ortan Puzzle

Following the tradition, there will be a central device with a green crystal to which you need to guide the streams. To quickly solve the puzzle, follow the step-by-step instructions:

• Dive underwater nearby and swim down until you encounter a group of Meks. Deal with them so they don't interfere with solving the puzzle;
• Swim to the right of the central device and interact with the Xenon Chromatic Armored Crab;
• Use the armored crab's ability to destroy the blockages nearby. They will be at the bottom of the ruin walls, identifiable by a distinctive blue glow;

• Beneath the stones, the Xenochromatic Ball Octopus will hide. Absorb its ability;
• Now you can interact with the mechanisms to activate the stream and direct it in the right direction. If the nodes light up with a blue light, you've done everything correctly;
• Use the armored crab's power to destroy another blockage near the device to activate the next source;
• Once you start the stream, a grid will rise nearby. Behind it will be a Mek blocking the path forward. Victory will reward you with a luxurious chest;
• Go back to the main room and direct the energy to activate the last stream leading to the central device.

Obtain the Personality Fragment

Approach the green crystal and retrieve the last seal needed to continue the quest "Search in the Algae Sea." You can find out how to complete the entire quest by following the link.

Rewards:

• 50 Primogems;
• 400 Adventure EXP;
• 30,000 Mora;
• 5 Hero's Wit;
• 3 Mystic Enhancement Ore.