The evening after the fifth years' Defense Against the Dark Arts O.W.L., the evening after James had strung Snivellus up in the air and Lily had intervened and Snape called her Mudblood, Sirius was headed back across the dusk-lit grounds to prepare for the full moon when he saw none other than Snivellus himself shuffling in the opposite direction. Immediately he changed course and headed for him, his lips twisting up into a sneer.
Hearing Sirius's approach, Snape whipped around and brandished his wand, glowering. "Get away from me, Black," he snarled. "I mean it." He sounded angrier and more dangerous than he ever had before; anyone else would have been deterred by such a tone coming from such a gifted wizard as Severus Snape. But Sirius was not anyone else.
"Upset that you've lost your girlfriend, mate?" he said instead with mock sympathy, tilting his head. "I've heard that tends to happen when you call them Mudbloods." Sirius hated how the slur tasted on his tongue.
"You have no idea what you're talking about," Snape said. "No idea—"
"Oh, I know exactly what I'm talking about," Sirius replied. "I grew up in a family where words like that were tossed around like Quaffles. That one in particular is one of my dad's favorites—he throws it at everyone from Muggle-borns to blood traitors. And trust me, Snivelly, you do not want to remind me of my father."
"No?" Snape grew a sneer that matched Sirius's own. "I know exactly how your father likes to treat you, Black. Regulus has told me all sorts of stories."
Sirius bristled at the mention of his brother's name. "Don't you dare bring Reg into this," he said through gritted teeth.
Snape raised his eyebrows. "My father likes to beat me, too—can't get enough of it when I come home for the holidays. You and me, we're really not so different."
Something snapped inside of Sirius. How dare he? "I'm nothing like you, you slimy, hateful little bastard!" Sirius raised his wand, but for once Snape was quicker.
"Sectumsempra!" he cried, slashing through the air.
A gash tore itself open along Sirius's hairline, bloody and painful as if Snape had taken a knife to it. Sirius fell to his knees and raised a hand to the wound, shocked. "What the hell kind of spell was that?" he demanded.
Snape stepped closer to him, his dark eyes bright with satisfaction. "A spell of my own creation," he replied. "It can do much more than a gash to the head—would you like to see?" He leveled his wand at Sirius's chest, and for once Sirius felt a flash of fear. He hated himself for it; it was the kind of fear only his parents could ever make him feel. You and me, we're really not so different. Why did he have to say that?
He forced a retort from his lips. "Meddling in the Dark Arts again, I see, Snivellus. You'll be quite an asset to the Death Eaters soon enough."
"As if you haven't been meddling with Dark Arts yourself, Black."
That caught Sirius off-guard. "What are you on about? I've never touched Dark magic before." That was too much his family's domain for Sirius to even consider.
"Dark creatures, then." The wand shook in Snape's grip. "Your friend Lupin…don't think I haven't noticed how he disappears once a month. Every month, like clockwork." Snape was trembling all over now. "The rest of this school might be fooled, but I'm not. I know exactly what kind of creature he is."
Anger burnt a hole through Sirius's chest. How could Snape call Remus a creature, this sniveling, trembling mess of a boy in front of him? But quickly the anger was replaced by fear, fear that Snape would reveal his suspicions to the school—even if the professors denied it, people would be bound to notice the pattern of Remus's disappearances afterwards, wouldn't they? Once the words Remus and werewolf were strung together, there would be no untangling them, Sirius was certain of it.
"Just you wait, Black," Snape was saying. "Your little group won't be so popular once your secret's out, now, will it?"
With stars in his vision and blood dripping into his eyes, Sirius forced himself to his feet. "You want to know the truth about Remus?" he snarled. "I'll tell you how to find it. Press the knot near the trunk of the Whomping Willow and follow the tunnel down beneath it. Then you'll have all the answers you want."
Something shifted in Snape's expression. "This is a trick."
"It's no trick," Sirius assured him. "Try it out—you'll see what I mean."
Snape stared at him unblinkingly for a long minute, trying to read something behind his eyes. "Immobulus," he murmured eventually, freezing Sirius's limbs in place. Then he took off silently across the grounds, his dark cloak fluttering behind him like the wings of a bat.
Sirius hoped fervently that it would be the last time he ever had to endure the sight of Severus Snape.
