for centuries it has been said that hogwarts is the safest place in all of the wizarding world, and for the most part you would be correct. hogwarts was built by four of the most brillant minds that the world has ever known - godric gryffindor, salazar slytherin, rowena ravenclaw, and helga hufflepuff. these four knew the most powerful of spells and magic to keep all dark and evil things away, and it was basically intangible. even when they had long passed on, the four's magic had binded tightly within the boundaries of the school and as long as the castle was still standing, all those within it would be safe from harm. unless of course the harm came from inside the castle already, meaning the staff and students.
with the threat of lord voldemort rising into power and control, many have sought the shelter and protection that hogwarts has provided, by either sending their precious children there or by trying to ge employed to have a place to stay. others have begun to flee britain in hopes that voldemort will not find them in far away countries like italy or russia. there have been numerous attacks on muggles and muggleborns, and it has been made clear that anyone with even a hint of muggle ancestry in their blood is not safe. purebloods are the only ones safe, with a select few halfbloods that have proved themselves loyal to voldemort with full understanding that they are inferior.
during his reign of terror, voldemort had killed more muggles and muggleborns than one could imagine. the world had been thrown into chaos and it wasn't until the mention of a prophecy that everything changed. the prophecy of harry potter defeating the dark lord was something that voldemort couldn't let happen, but after seventeen years of trying to defeat the young potter, he failed miserably. in the middle of the great hall of hogwarts, harry potter succeeded in killing the one man that terrorized the wizarding world more than grindewald had. finally the world was at ease and everyone could breathe easy.
it had been over two decades since the fall of voldemort and the wizarding world is still in a state of peace and calm. families had been formed and everyone was enjoying life. but in the far shadows of the wizarding world, a rumour of a new, unspeakable evil has risen. after all these years, rodolphus lestrange had been in hiding, vowing that he would get revenge for his wife's death. he would continue to strive for what his late master had tried to ensue, and he would damn well do it right this time. rodolphus had been gathering up any and all forces he could, mostly old death eater members that had gone into hiding. he christened the group the walpurgis knights and this time they were going to be successful, or so he hoped.
now the children of the last generation have grown up and are in hogwarts. they're busy studying for their classes, partying or doing whatever they please. as the wizarding world keep a blind eye to any sort of rumour of the evil in the shadows, rodolphus is taking the time to get the children of the walpurgis knights ready to strike within hogwarts walls. so keep your eyes and ears open because everything must change eventually.