Young teacher, the subject
Of schoolgirl fantasy
Not this one.
"Saturnine" might have been the kindest description. Scrawny, dark eyed, unkempt. Not a happy bunny. Don't even mention what they had called him.
Not that long ago, either.
The other Heads of House tried to support him. Dumbledore . . . not so much. Slytherin House was still waiting. Waiting now to see what he'd do about the continuing thefts from the potions supply cupboard. Dunderheads.
Severus Snape took a deep breath and considered his options.
He could keep an eye on things in the classroom. He could not when doing rounds. Or sleeping. (He'd been forbidden from sleeping in his private lab which opened onto the other end of the storeroom). With magic, time and distance matter. His request for the services of a house elf had been refused and the Dark Arts were right out.
Time, it would seem, for a different approach.
The following morning there was a new lock upon the door. Large, grey painted and screwed to the interior of the door with a hole drilled through to allow the key to be used from the outside, no one was impressed by it. The more observant amongst the students noted that there was also something chalked onto the frame above the door. "POSUI CUSTODEM SUPER EA." By afternoon there was mention of a medievalist scholar named Montague Rhodes James, a story titled "The Treasure of Abbot Thomas" (and what became of the person who found it), and that there were other stories and books by the same author in the library. There was also general agreement throughout the school that the current Head of Slytherin was "Definitely the Type" and, consequently, a degree of circumspection if not quite actual terror.
Four days elapsed before Snape found himself being invited to the Headmaster's Office to explain himself. 'Actually, I'm on my way to the Hospital Wing. Madame Pomfrey has again requested my assistance,' he told the face in the flue politely. 'Perhaps we could meet up there?'
Hogwarts' youngest Potions Master ever found himself escorted from the school in chains.
Later he returned at the head of a small team from Saint Mungo's, his expertise being required to diagnose and (it was hoped) treat a potions mishap suffered by students who, having broken into the supply cupboard, had encountered something unexpected - to whit, a volatile and hallucinogenic spillage (resulting from the breakage of various jars when struck by the key being magically expelled, at speed, from the lock) - and could now not be dissuaded from hopping, bouncing and flapping weightlessly around the hospital wing (all the while screaming), by any means save deep unconsciousness.
The Aurors investigating were furious. 'So,' breathed Moody, 'you set an alarm for the key being turned by magic? And that was it? "Depulso" pushes the key out of the lock and "Accio" gets it back under the door. Then open normally. How was a muggle lock going to stop anyone with even the slightest bit of intelligence?'
He couldn't agree more. Indeed, that had been the point. Snape sighed. 'It is still,' he pointed out, 'more than was there before. My concerns regarding students poisoning themselves, and each other, as well as the security of the cupboard are all on record, as is a refusal to countenance stronger measures. Perhaps you might try addressing your concerns to the Headmaster?'
Madam Pomfrey, not unexpectedly, agreed with him quite forcefully until the Aurors decided to take matters elsewhere.
Years later, school lore still maintains that Snape has set some kind of Guardian over his domain. Off course, some students will believe anything they're told while there are others that are oblivious. Every school gives rise to its own mythology but this is not just any school - this is Hogwarts School of Witchcraft and Wizardry. Here, words have power. Belief can change things, summon things, even call things into being.
Perhaps this is the beginning.