How do you get past the hospital wing in Lego Harry Potter?

1. Start by interacting with the door to the Hospital Wing. This will cause a cutscene where Madam Pomfrey catches Harry, Ron, and Hermione and escorts them back to the Gryffindor Common Room.

2. Once you are in the Gryffindor Common Room, talk to Nick-Nearly-Headless. He will tell you about a secret passage that leads directly to the Hospital Wing.

3. Follow the instructions that Nick-Nearly-Headless gives you to find the secret passage. It is located in the wall behind the staircase leading to the boys' dormitory.

4. Enter the secret passage and use the Polyjuice Potion to disguise yourself as Crabbe and Goyle. This will allow you to sneak past Madam Pomfrey and enter the Hospital Wing.

5. Once inside the Hospital Wing, you can find the item you are looking for. It is located on a table next to Ron's bed.

6. Use the Invisibility Cloak to sneak out of the Hospital Wing and back to the Gryffindor Common Room. This will avoid alerting Madam Pomfrey to your true identity.