In the Shadow of the Undercroft – Hogwarts Legacy Quest

In this walkthrough of the Main Story quest “In the Shadow of the Undercroft”, we’ll guide you as Sebastian shares a sweet new spell, and you share some secrets in return.

• Quest Type: Main Story
• Location: Astronomy Tower, Hogwarts Castle (map)
• Requirements
  • Level 8
  • Complete Flying Class
• Rewards
  • 260 XP
  • Confringo

Meet with Sebastian

Sebastian is waiting for you near the Astronomy wing — your closest Floo Flame will likely be the Defense Against the Dark Arts Classroom, so use the closest fast travel point, then continue to your meeting spot (press if you need guidance from your compass). If you don’t see Sebastian, try looking away from the meeting spot, as he will sometimes not load in while you’re looking at where he’s supposed to spawn. Once you find him, speak with him by pressing /

Enter the secret room

When your conversation ends, follow Sebastian, and he’ll lead you to a strange looking clock. Walk up to it and hold / to enter the Undercroft.

Explore the room & Talk to Sebastian

After a brief cutscene, you’ll find yourself in a large chamber. Sebastian will chat a bit — once he falls quiet, your objective will change to “Talk to Sebastian”, at which point that’s what you’ll need to do: walk up to him and press /. After another conversation, he’ll teach you Confringo. The sharp turns of the Z shape can make this minigame tricky, but you’re an accomplished spell caster by now! Don’t forget to look ahead at the required buttons before starting the casting attempt.

Practice using Confringo

Open your Spell Menu with and put Confringo into your Spell Diamond. Then you’ll need to cast it on the three candelabras in the room — one in the northwestern corner, one to the east, and one to the south. The spell has good range, but if you’re having trouble hitting one of the candelabras, hold to aim carefully before casting Confringo.

Check back with Sebastian

After you’ve destroyed all three candelabras, go back to Sebastian and press / to speak with him once more. He’ll get you talking about your Ancient Magic abilities, and then it’ll be time to go.

Leave the Undercroft

Head to the door you came in, in the northeastern corner of the chamber, and hold / to leave the Undercroft. Upon exiting, you’ll be accosted by Ominis Gaunt. When your conversation with him ends, you’ll have completed the quest! Next up, The Map Chamber.

Return to Main Menu

The Map Chamber