Recent revelations show that the Shack might not be as haunted as we thought. In the third installment of the Harry Potter series, Harry Potter and the Prisoner of Azkaban, we learn that the noises that used to emanate from the notorious Shack in Hogsmeade Village were actually caused by Remus Lupin, Ex-Defense Against the Dark Arts Professor, close friend to James Potter & Sirius Black and Werewolf.

Because of a bite he received at a very young age, Remus was considered to be an outcast. Turned away from all the best Wizarding schools, until Professor Albus Dumbledore was appointed as Headmaster at Hogwarts School of Witchcraft and Wizardry. Dumbledore, sensitive to Remus' predicament allowed Remus to enroll in the school, and enforced precautionary measures to ensure the safety of all students.

Every month at the full moon, Remus was led into the school grounds, towards the tree that is fondly known as the Whomping Willow, which was planted specifically because of Remus, where a small knot on the tree was pressed. Pressing this knot would stop the branches from moving, and allowed Remus access to a tunnel beneath the tree, which led directly to the Shack, where he would spend the night.

Remus made some very close friends while at Hogwarts, James Potter, Sirius Black and Peter Pettigrew. Remus kept his condition a secret from the three, scared that if they found out, that they would turn their backs on him. Regardless of his discretion however, his friends grew curious, wondering where their friend went to each month on the full moon, and set to work to find out what the secrecy was all about.

Remus' fears turned out to be redundant. Instead of turning their back on him, James, Sirius and Peter proved their loyalty to Remus in the most amazing way. Breaking nearly every Wizarding rule, the trio studied hard for almost three years and became illegal Animagi, and would spend the full moon with Remus in his wolf form, inside the shack.

After sometime, the four friends, in animal form, took to roaming around the outskirts of Hogsmeade Village, enjoying the special bond that made them such good friends.

Even though Remus Lupin has now left Hogwarts, and there is no longer ghostly sounds emanating from the Shack, people still believe that it is haunted and no doubt they will for a great many years to come.