Cache In The Castle is a side quest you can complete in Hogwarts Legacy if you want to get your hands on an Authentic Historian’s Uniform. This side quest will also get you 180 XP on completion, which is good if you want to level up and fight tougher enemies. However, if you don’t like treasure hunts or don’t have patience exploring your surroundings, this quest can cause problems.
To start this quest, first, you need to complete the Welcome To Hogsmeade story quest. Next, you need to find Arthur Plummly, located in The Astronomy Wing area of Hogwarts Castle. As such, you’ll need to open the Hogwarts map, select the Astronomy Wing flag on the castle’s east side, and track the quest by pressing X above its icon.
The tracker should help you find Arthur Plummly, and if you have the Charms Classroom Floo Flame unlocked, you can fast-travel there. The quest giver is close to the Charms Classroom Floo Flame if you have problems finding him. All you have to do is go down the stairs north of the Floo Flame and turn left to find the mission giver in front of a big window.
Talk to Arthur to find out more about his map.
Where To Find the Skeleton From Arthur’s Treasure Map
The NPC will give you a treasure map on which you can see a couple of landmarks. The first one you must reach is the rhinoceros skeleton.
To easily find the first landmark, you must go down three floors using the stairs to the north upon speaking with Arthur. Once on the right floor, head to the railing to your left, and you should see the rhinoceros skeleton between two globes on the lower level. Make your way to the skeleton and position yourself in front of it to discover the first Cache In The Castle landmark.
Where To Find the Dragon From Arthur’s Map
For the second landmark, go down the stairs west of the rhinoceros skeleton. Then, go outside through the door in front of the stairs. The second landmark is the fountain in the middle of the garden.
Where To Find The Third Landmark From Arthur’s Treasure Map
Now, you have to head northwest of the previous fountain and go through the door in front of the big tree. Once inside, go forward about ten meters and turn right to see some stairs going up. It seems that the stairs are the third landmark in the quest.
Where To Find Arthur’s Map Painting
Now, you must find the painting in Arthur’s treasure map. As such, go up the first two sets of stairs, and you should see the painting on the wall to the left, near another skeleton, as shown in the following screenshot.
How To Discover The Painting’s Secret
The secret to the painting is pretty easy to decipher if you pay attention to the treasure map one last time. On the treasure map, you can see a hand near the painting, symbolizing the Accio spell. With that in mind, aim at the painting and use the spell by pressing R2 + Square to open a secret door hiding a chest.
Open the chest to get the Authentic Historian’s Uniform and head back to Arthur Plummly near the Charms Classroom Floo Flame to complete the Hogwarts Legacy Cache In The Castle side quest.
In that same room as the painting, there is another room you can’t access behind the skeleton in the glass case seen in the picture.