Disclaimer: Harry Potter belongs to J.K. Rowling.
A/N: takes place post–Deathly Hallows. This was inspired partly by the book Sabriel, by Garth Nix.
Harry's POV
Perfect. It's what everyone expects me to be. I'm the Chosen One, and so a saint by default. How far that is from the truth, which seems utterly pathetic in comparison. I defeated Voldemort like I was supposed to, but there was a price even for that – countless people on Dumbledore's side had been killed. As far as I know, all the Death Eaters, with the exception of Snape, were either dead or imprisoned. Severus has lived with me since shortly after the war, but for several months he's refused to speak to me.
One day Severus left a thin, green cat collar on the kitchen table. Beside it lay a thick book open to a chapter on alternative transfiguration. As I read it, I found that the spell it described would leave the spell-receiver in whatever animal form the spell-caster visualized in his or her mind, but the receiver would still be able to think and reason with a human mind. However, a collar bearing the appropriate charms was required in order to bind that person to the animal form, and only the one who put the collar in place could remove it again.
Taking Severus' obvious hint, I gathered up the book and collar, found him waiting in the living room, and performed the spell. I met no resistance as I fastened the collar around his neck. Once the collar touched his bare skin, he rapidly began to transform, his body shrinking, long, thick fur sprouting all over him. Barely a minute had passed before a small cat stood in front of me. Severus' fur and eyes were just as black as they had been when he was human.
When I tentatively reached out a hand to touch Severus, he backed away, dark eyes watching me warily. "I'm not going to hurt you, you know," I informed him distractedly. I'd suddenly realized that I didn't know why Severus had wanted to be transformed, or what his plans were. Naturally, I'd simply ploughed ahead without thinking.
Severus padded towards the front door, head turning back expectantly. "You can still stay here," I said, only to have my offer immediately dismissed with an irritable twitch of Severus' tail. Of course he didn't want to spend anymore time with me. He'd already put up with me for seven long years at Hogwarts, and now the several months here. It was stupid of me to even think of getting my hopes up, but I couldn't stop the ache that resonated hollowly in my chest.
After Voldemort's fall, I had found it nearly impossible to pick up all the pieces of my life and fit them back together again. My friendship with Ron and Hermione was strained at times; and my and Ginny relationship had not survived at all. The two of us had grown more and more distant until it became clear that breaking up was the less painful choice.
After Ginny moved out, I'd slowly noticed the strangeness of being all alone. When I finally managed to convince Severus to take refuge at my place, I tried so hard to tell myself the reason was because I felt sorry for the other man. Deep down though, I knew the truth – I wanted, needed someone there with me, and I'd even began to enjoy Severus' silent (albeit often invisible) company. Now that I was being forced to watch him leave too, I tried in vain to ignore the loneliness that yawned inside me.
I walked to the door slowly, resting my hand on the knob for a few seconds before Severus mewed loudly. I looked down at the cat, and before I could change my mind, I swung the door open. Severus slipped through and bounded away, never bothering to look back.