Wormtail slithered through the library. The route was familiar, and he made his way easily among the vast bookshelves despite the darkness. It was just before midnight at Spinner's End, and he was spending a customary evening behind the bookshelf in Snape's rundown house.
Behind the bookshelf was a staircase that led to a small library, and he spent most of his time leafing through the dusty old volumes and waiting for Snape's return for the Christmas Holidays. Snape was supposed to arrive at midnight, and Wormtail rubbed his hands together in anticipation. He reached out and glided his finger softly over the rough book covers, then paused at an enormous red book at the end of the second shelf. His lips curled into a malicious smile as he carefully removed the book and cradled it in his arms. His most prized possession, and Snape had always ignored it.
He rifled through the yellowing pages until he came to the very last potion, which promised to be the most powerful yet, although he wasn't exactly sure what it did. Contact with this potion, he read, will induce a rare and frightening Muggle disease in the unknowing victim. Squinting down at the final ingredients, Wormtail turned to a shimmering metal cauldron in the center of the library. He dropped in three human eyeballs, listening to them plop into the hot liquid and then slowly sizzle to the bottom. Then he reached into his pocket, shuddered, and added the rat poison. The potion turned green and began to bubble threateningly. "This is for you, Snape," he said, his voice quietly resonating through the dark library. "My Christmas present to you."
Snape resented having to spend the Christmas holidays with Wormtail. It was maddening to have to endure the rat's company for two entire weeks. He slipped into a pleasant daydream of Wormtail lying dead behind the hidden door in the bookshelf as he made his way through the long grass that grew by the river. Garbage lay everywhere, and he secretly relished the familiar rotting smell that always rose from the bank. As he turned onto Spinner's End he stopped and briefly admired the surrounding houses. Ruined, abandoned and neglected – it was just the place for him. He came up to his house at last and squeezed his narrow frame through the doorway. Darkness greeted him as he made his way inside.
It was ready. Wormtail carefully scooped a generous amount of the potion into a flask. Then, he went over to the door and opened it just a couple inches, shivering with excitement. With the aid of a chair he balanced the glass between the top of the doorframe and the wall, so that it would fall as soon as the door was opened. Another little trick he had learnt from Muggles. It was difficult to suppress the nervous sniggers that threatened to erupt from his mouth. He sat down behind a bookshelf and cradled his knees in his arms, listening to Snape's movements downstairs. They would be the last movements he would ever make.
Snape sensed a change in the room as soon as he stepped inside, but it was hard to pinpoint exactly what it was. The grandfather clock on the wall seemed to be ticking a little too loudly, as though trying to communicate some ominous secret. He could feel recent magic in the air, almost tangible in the old rundown house. Wormtail was nowhere to be seen. He waved his hand over a wax candle and it instantly became ablaze, the flickering light casting long shadows across the room. Snape cautiously made his way to the bookshelf. "Wormtail?" No answer. He began to grow annoyed. He was getting a bit too old for hide and seek, he mused grimly as he opened the hidden door. He thought he heard a quiet bubbling noise as he made his way up the stairs. "Wormtail, show yourself this instant!" His candle fluttered and blew out.
Wormtail had to cover his mouth with his hand. He was coming! He peered through a crack in the bookshelf and saw Snape angrily swing the door open and enter the room, still clutching the burnt out candle. The precariously balanced flask came crashing down on his head, the liquid spilling into his hair and down the nape of his neck.
At first Snape felt nothing. He wondered what the little vermin been thinking. That he, the Potions master of Hogwarts for so many years, could actually be harmed by a potion? The idea was ridiculous. There was not a potion in the wizarding world he was unfamiliar with, and he could undo any of their nasty effects with a swish of his wand. There was no need to be afraid, he told himself. Then an anxious and unpleasant feeling began to spread through his body. Germs became visible in the air, leaping onto his skin and infecting his body and brain. A piercing scream filled his head and he realized that it was coming from himself, from what seemed a long distance away. The world suddenly became full of numbers, and repetition suddenly became extremely important. "Help!" he screamed. "Help help help help help help help help!" He frantically grabbed his wand. Perhaps some light would ease his panic. "Lumos !" he screamed. "Nox !" "Lumos nox lumos nox lumos nox lumos nox lumos nox !" It was no good. Perhaps he could find refuge in the incessant ticking of the grandfather clock downstairs. Snape took four steps toward the doorway, tripped and fell, smacking his head audibly on the fourth step. Blood gushed freely from his forehead as lay at the bottom in a crumpled unconscious heap.
Wormtail stood at the top of the staircase, gazing down at the unconscious form with delight in his eyes. He would savor the image forever. Snape, defeated at last, lying in a helpless heap on the floor. He reached into his pocket again and this time produced a gleaming pair of scissors. He ran down the stairs lightly, as though he shed ten years with every step. When he reached Snape he savagely cut away a clump of greasy black hair and laughed. Just enough for a big batch of Polyjuice potion. Wormtail closed his eyes and imagined himself as a new faculty member at Hogwarts. The mischief he could cause! It was going to be an interesting year…