Voldy-lord

The Restricted part of the school library, though impenetrable, was a kenspeckle area. Housing books of the deepest, darkest magic, of inestimable value, exquisiteness - like golden dust. For pupils must leap sure-footed through hoops, presenting upon the Librarian a unique letter of approval. And then, only then, might they be presented with their desire.

One such book contained a great deal of potions. Potions of one type - potent, menacing, intricate, ghastly, arcane. Within the covers contains the potions of Polyjuice and Laxative.