This walkthrough will guide you through all the objectives of the side quest “In the Shadow of the Study” in the game of Hogwarts Legacy. You are going to learn Crucio spell in this quest which is an Unforgivable Curse spell
Meet Sebastian outside the Slytherin common room
To begin the quest, go to Hogwarts’ Slytherin Common Room and speak with Sebastian. He will express his desire to study more about the Dark Arts, but Ominis will not reveal the location of Slytherin’s Scriptorium.
If Sebastian isn’t standing outside the Slytherin common room, you can wait in a glowing circle for him to make him spawn.
Go with Sebastian to meet Ominis
Follow Sebastian until he leads you to Ominis and then speaks with Ominis. He will tell to light three braziers
Open Slytherin’s door
To open the Slytherin door you must light three braziers. Two braziers are down the hallway and one brazier is to the east. Light the 3 braziers with Incendio. Two braziers are in north corridor and 3rd is on east corridor.
Explore beyond the doorway
Go inside and downstairs.
Figure out how to progress
Pick up a letter from Noctua Gaunt and then cast Reparo on the floor debris.
Speak with Ominis about the hissing & Wait for Ominis to open the door
Talk to Ominis and wait for him to open the door and
Explore beyond the Serpent Door
Head inside the serpent door.
Find a way through
#1 Slytherin Lock
Once inside you will find a locked Gate-1 to your right with some symbols and a Slytherin Lock. light the flame with Incendio and then rotate the lock to match the symbols to the one that matches the locked Gate-1. Just open the gate don’t go through this.
#2 Slytherin Lock
Go to the corridor to your left to find a broken Gate and a locked Gate-2. Crouch through the broken gate and then light the flame with Incendio. There is a Slytherin Lock near the flame. Rotate the lock to match the symbols to the one that matches the locked Gate-2.
#3 Slytherin Lock
Go inside Gate-2 to see the pattern for the locked Door-3. Now, head inside Gate-1 which you open earlier to find another Slytherin Lock. Rotate the lock to match the symbols with Gate-3. This will open gate-3 and you can enter inside. Also, grab another of Noctua Gaunt’s notes just to the right of the mechanism
Talk to Sebastian
Head inside and you will get locked with the Crucio and a note on the floor. Then speak with Sebastian.
Wait for Sebastian to talk to Ominis and Talk to Ominis about Crucio
He explains what needs to be done and asks that you speak to Ominis about Crucio.
Explore beyond the doorway
Head inside and cast Revelio to highlight where important items and chests are
Search Slytherin’s Scriptorium
Pick up Slytherin’s Spellbook on the altar in front of the giant statue and give the book to Sebastian
Leave the Scriptorium
Follow the waypoint to the statue behind. You can exit by interacting with the statue.
Listen to what Ominis has to say
The quest will be completed after Ominis and Sebastian finish the conversation.