There are still many children's shoes in Baldur's Gate 3 who still don't know the guide to entering the underground passage of Baldur's Gate 3 Song of Dark Night, so let's take a look at the "Baldur's Gate 3 Song of Dark Night Underground Passage" shared by the editor below. Take a look, I hope it helps everyone.
1. Come to the location shown in the picture on the west side of the Goblin Fortress.
2. Afterwards, the player kills the priestess's personal guard, Polma.
3. You can get the Priestess's Diary from the wooden box near the guard.
4. Interpret the contents recorded in the diary to get the answer to the decryption of the moon disk.
5. Follow the four full moons at the top, the four new moons at the bottom, and the left and right half moons to unlock the trap.
6. After the mechanism is unlocked and opened, we can enter the dark area through the secret door.