Everything belongs to JK Rowling.

Adult story of SS/RL considering the nature of duality, victimhood and impossibility of forgiveness.

DUALITY

Chapter 1

It was coming up to the third full moon since Lupin had taken up the post of Defence Against the Dark Arts professor. Snape had noticed that Lupin's behaviour became increasingly strange as the full moon drew near. He would feel the hair on the back of neck rise, and when he looked around, he would invariably find Lupin in the vicinity, watching him silently. Lupin would hold his gaze then move away, but Snape found it unsettling nonetheless and it happened with increasing frequency. When the full moon had passed, Lupin would revert to his insufferably amiable self. The same thing would happen at the next full moon. He noticed Lupin seemingly following him more and more. Tracking him? Hunting him? Snape did not consider himself a fanciful man, but he found his heart racing with the thrill of fear each time he caught Lupin staring at him, his lambent stare deep and searching. He started to avoid Lupin completely and found himself fearful. He Occluded his mind so none should see his weakness.

It was the night before the full moon. Snape took the wolfsbane potion to Lupin and left it on his desk, adjuring him to drink it without delay. It was part of a regimen beginning before the full moon to allow a werewolf to retain its human mind during its transformation into the wolf to render the creature safe. It was fiendishly difficult to brew, but not for Snape, the Potions master.

Lupin had looked directly at Snape when he set delivered the brew. Lupin's features had an odd cast: they seemed harsher, sharper, more predatory. His eyes seemed to glow golden, bright and deep. Snape fancied he saw the wolf glide past. Lupin stood. His usual stance was somewhat passive, but not tonight. He looked commanding but on edge. Snape's acute sense of smell seemed to be assailed by a musky scent that became pervasive. Lupin had moved next to Snape and murmured close to his ear, before Snape could react, "Thank you Severus" and chuckled. His voice was deeper than usual, menacing, almost a growl. He backed away one step, smiling none too pleasantly and drank the potion. He passed the cup back to Snape, not quite relinquishing it, chuckled, and then moved back to his chair. Snape was disconcerted. Perhaps it was usual for the wolf to stir so visibly the night before full moon. Snape had not heard of it before. He would research it. He left Lupin, still impudently leering at Snape.

It was time to turn in for the night. As Snape was disrobing, when there was a firm knocking on his door. "It is I, Remus Lupin."

How odd, thought Snape, concerned there was a problem with the potion he had brewed. As he opened the door, and the wolf came through, shutting the door. It only took one look at Lupin's face to see the wolf fully behind his eyes. In that instant, the wolf had jammed Snape against the stone wall, his weight behind his right forearm braced across Snape's chest, pinning him. His left hand held Snape's right wrist behind his bank. Nose to nose, golden eyes entranced the black. Snape felt his strength drain, his will sapped, and abject terror rising in his throat. The wolf visible in the eyes, breathed in and out heavily, its breath hot whilst scenting the air around him; the creature reeked muskily. Snape was voiceless; he was powerless; he could summon no magic to his aid. The proximity of the Dark wolf in the wizard's body had in some way Snape did not understand drained him and he was helpless. The wolf as wizard charmed the door locked and warded for sound.

"I have watched you Severus for so many years. I have desired you," the wolf growled, its voice deeper than before. "And now, I am free to take you." Snape struggled but uselessly. The wolf's grip was like iron. The wolf threw Snape to the floor and advanced upon him.

It was some hours before the wolf was spent. He left Snape unconscious on the floor where he had used him. When Snape came to, it was not yet dawn. He was badly injured and bleeding. He was free of the wolf's magical binding and he Summoned his potions and unguents to him to start to heal himself, just as he was used to doing if he had incurred the Dark Lord's displeasure. As these took effect, he managed to bathe and then to start to repair his rooms which were in disarray and burn his torn clothes. This done, he sank to his knees, weeping silently. How had this happened? How had he lost his power? How had Lupin contrived that none should hear and none should save him – here, where he had always been safe from the Dark?