The Count Lucanor (EP)
33 Achievements
5-7h
A red light
Use the snake ring at the best place.
61.7%
How to unlock the A red light achievement in The Count Lucanor - Definitive Guide
I have a 100% Achievement Guide for this game if you prefer a visual!
As you progress through the game, the Goat herder will turn up in the courtyard (Although, missing some crucial items on himself)
Talk to him and he gives you a red key. By this point you SHOULD have by now the snake ring in your inventory.
So when you have the ring and red key, head left from the courtyard, and keep going directly left until you see a door.
BEFORE you enter, simply equip the ring and then you can enter, unlocking this achievement!
Go to 41:05 to see how and where this achievement is done!
Hope this helps!
In order to be able to unlock this trophy, you will need to give your cane to the old woman at the beginning of the game. After meeting Giulia for the first time, go back to the fountain room and talk to the old woman. She will give you the green key (and the snake ring, provided you gave her the cane). Do not equip the snake ring yet.
Keep playing through the game until you get the red key from the goatherd in the garden. Once you do, use the left exit and go left to the red key door (the chest room). Place a candle in front of the door (so you're not in the dark), equip the snake ring, then enter the red key door. Walk forward a bit into the room. Once Hans finishes talking, the trophy will unlock.