A/N: I swore to myself that I'd never write Harry Potter fanfiction, because there were so many people out there doing a much better job of it than I ever would. Well, lookie this. Snapefic. I don't even particularly like Snape. Eh, blame it on Rickman in the PoA movie.
Disclaimer: I forgot this the first time around. All characters and events depicted herein belong to JK Rowling and whomever else she's licensed the series out to (I can't remember it all and am too lazy to go find out), including but not limited to: Bloomsbury Books, Scholastic, and Warner Bros. The wording's mine, if you please, and this view on Snape is mine, also.
Watchfulness
It is harder to play the villain than the hero. Severus knows this well – notes with equal parts disdain and injury that what students do not hate him are the sons whose fathers he betrayed, thirteen long years ago.
And it is the werewolf who nearly killed him when he was still a student, the friend to the most famous traitor during the War – whom the children love.
He does not hate Remus Lupin for the post of Defense Against the Dark Arts; he thinks it wrong that a creature of the Dark should be warding children against the very force to which the teacher has succumbed. It is not Lupin he loathes, precisely, though he will not deny that he cares little for the man. Severus feels no pity for a self-made martyr, not when he spent years in the service of Voldemort and saw far worse.
It is only out of loyalty to Dumbledore that he brews Wolfsbane potion for him, and only out of loyalty to the Order that he has not yet betrayed Lupin's secret to the board of governors, and Lucius Malfoy.
He knows that they expect him to, his fellow staff members – to reveal Lupin as he once attempted, when they were all schoolboys. Perhaps he will; he will do whatever is best for the children. They may hate him, his students, but he still cares for their safety, if not them. He has doubts as to whether Lupin could resist Black, even after these twelve years of stewing in the blood of ruined friendships. After all, the man couldn't, even at Hogwarts, with the gilt badge of a Prefect pinned to the breast of his worn second-hand robes. Severus doubts that near a score of years will have changed anything.
He doubts that near a score of years will have changed him from Lupin's scapegoat into his ally, and that bothers him little enough. He has not yet poisoned the Wolfsbane Potion, and whether or not Lupin regrets the necessity that forces him to seek out Severus to make it does not trouble his sleep at all.
Frankly, if Lupin is content to let history lie, then so is Severus, but it seems that wretched Harry Potter would wish to dredge it all up again, to claim injury by Severus's hand and kindness by Lupin's.
It is no wonder, then, that Severus is angry. While he is left cold in the Slytherin dungeons, watching for the children's safety as they glare at him, Lupin will betray them all to Black, and yet it is Lupin the children love.