How to solve the Central Hall door puzzle in the Library Annex in Hogwarts Legacy

The Hospital Wing is the medical wing of Hogwarts Castle. It is home to Madam Pomfrey and the Hogwarts Hospital staff. It is also the place where Hogwarts students can seek medical attention and treatment. As part of your journey in Hogwarts Legacy, you must find your way to the Hospital Wing in order to progress further in the game.

In order to progress further in the game, you must find the Magical Paintings Conjuration exploration collectible. To find this collectible, you must first get past the students and professors and find your way to the Hospital Wing. 

To start your journey, you must first speak with Gladwin Moon to start The Caretaker’s Lunar Lament quest. This will give you the knowledge and tools necessary to get past the enchanted door. In order to pick the lock of the door, you must use the Alohomora charm. Once you cast the charm, the door will open and you will be able to enter the enclosed area. 

Once you enter the enclosed area, you will encounter several students and professors. In order to get past them, you must use the Disillusionment charm and the invisibility charm. These will help you pass Professor Weasly and Professor Sharp and make your way up the staircase to your right. 

Once you reach the top of the staircase, you will find a door that is locked. To unlock the door, you must roll the triangle next to the door until the spider appears. Similarly, the bottom triangle is 5+9+??=17, so the missing creature is 3 (the hydra). Go upstairs and roll the triangle above the locked door until the hydra appears. Interact with the door to open it and access two chests, one of which contains the Magical Paintings Conjuration exploration collectible.