There are a few quests in Hogwarts Legacy that make you scratch your head and this Cache in the Castle quest is one of them. The quest can be obtained from a Hufflepuff named Arthur Plummly, who can be found inside the Astronomy wing to the left of the Charms Classroom Floo Flame. Go down the set of stairs and make another left, and you will see Arthur there calling out for help with something as they look at a map. The quest can also be seen and tracked on the Hogwarts Map by clicking on the Astronomy Wing Floo Flame Locations, and then selecting the quest with the corresponding "track" button. This will lead you right to it as well.
Arthur tells you they have found two treasure maps that show some hidden goodies around Hogwarts, and asks if you would like to take a look at one yourself. You will then be told you can keep whatever you find, as long as you tell Arthur where the map leads after the fact. You will then be given a map that looks like this:
As you can see, as with the Ghost of our Love quest, you are given a map to follow with landmarks to use as a guide. This one shows a large skeletal statue, a dragon-like creature slithering down a pole, a painting with the Accio spell above it, and another statue of a dragon in a courtyard with a doorway behind it.
These are the landmarks you will need to look for, and the map stays in your inventory for you to reference it at any time.
How To Complete The Cache in the Castle Quest in Hogwarts Legacy
By using the map given to you by Arthur, you will need to head to the first location on the map, which is the large rhinoceros skeleton. This skeleton can be found inside the Astronomy Wing. Starting from where you got the quest, turn around and go down the sets of stairs in front of the statue holding an orb (there are about six flights of stairs for you to go down.) Once on the floor that contains the string instruments playing music, you will make a left and head down yet another few flights of stairs. If you look over the railing to the left of the stairs you came from, you can actually see the skeleton in the center of the room downstairs.
Next, you will need to find the Dragon Statue from the map, which can be found in the Transfiguration Courtyard. You can either fast-travel from the skeleton statue to get here, or simply run down the flight of stairs to the right of the statue and head directly outside to the courtyard through the large set of double doors directly in front of the staircase.
Once in the courtyard, you will see the statue from the map in the dead center. The set of double doors from the map can be found directly behind the statue (the direction the Dragons Tail is facing). Go through those doors and make an immediate right up the set of stairs. Go up two flights of stairs, and you will see the painting from the map on the left-hand side of the staircase. Walk up to the painting and use the Accio spell while aiming at what looks like a door knocker on the top of the frame.
This will reveal a door that you can walk right through to find the treasure chest!
The quest will then bring you back to Arthur once you have looted the chest, which can be found again in the same spot room you picked up the quest initially. Rather than go left from the Floo Flame near the Charms Classroom, you will see Arthur staring at a painting on the wall directly in front of the flame across the room. Arthur tells you what they found and you tell them what you found and the quest is then completed automatically.
That concludes our Hogwarts Legacy Cache in the Castle Quest Guide! Notice something we didn't? Drop a comment below!