The Impressionist Mechanism
Remus Lupin liked people. On the whole, he thought they were a good sort, but it wasn't just that he liked people because they were interesting. He liked the physical human body, the shape and strength of it, even though his body wasn't human anymore, not really. He liked watching people who talked with their hands, using gestures to emphasise words. He liked watching trained runners sprinting, and trained dancers dancing.
What he liked most was the shift and curve of the spine under the skin of a bare back, the way muscles rippled across it. Science classes, before Hogwarts, taught him that the spine was central to the nervous system, almost as important as the skull and brain. During one of his father's quests for a cure, Remus had learned a lot about the line of the spine and the way it affected the body's nerves, the way all muscles were interconnected, and how that connectedness altered during the transformation from man to beast.
Vertebrae themselves were lovely, weren't they? A perfectly functional interlocking set of bones that were formed in beautiful abstract shapes, like a machine built by an impressionist artist. As a student, rambling through the wilderness around Hogwarts, he'd once found a nearly complete skeleton of an owl who'd met some sort of unfortunate end. He'd studied the spine a long time before respectfully kicking a bit of dirt over it as a burial.
When Professor McGonagall took him into Hogsmeade for his first shopping trip as a proper Hogwarts Professor, she pointed out that the candles in the Dark Arts classroom needed restocking. One of their first stops was at Illumos, the Hogsmeade candle shop, since electricity didn't work in the castle.
"Something properly eerie, I think," she said, as they drifted through the shelves of plain white pillars, specially designed dribbly-candles, divining tapers, trick tea-lights, and other charmed wax creations. "Dark Arts does have a reputation to maintain, after all."
"Hmm," he answered, unwilling to purchase frivolous dragon-shaped candles or ones that shot two feet of flame in the air, even on the Hogwarts supplies expense account.
"Black is always effective, I've found," she was saying, but something on the overstock shelf in the back caught his eye, and he slipped past a large cabinet full of grinning skulls and house-elf heads to pick up one of the cut-rate candles, running his fingers over the sinuous shape appreciatively.
"How about these, do you think?" he asked, turning to her and holding it up. She raised an eyebrow.
"No-one can deny they're appropriate," she said reluctantly, "but perhaps a little too macabre..."
"Oh, I don't think so," he answered. "There's lots of them and they'll last a long time, and it's a lovely shape, and anyway they're dead cheap. Look," he added, "the vertebrae are even marked, so you can tell which one you're looking at. Light source and anatomy lesson all in one."
He lit one with a pinch of his fingers and a flick of the wrist, and grinned at her over the flame. She smiled back, the indulgent, I've-been-sweet-talked smile she used to give him when he made jokes to get his mates out of trouble, back when he'd been her student. She blew out the flame, and gestured at the shelves.
"Have them sent up to the castle, then," she said, and he made his way to the till. "Don't dilly-dally, Lupin, you've more supplies to buy..."
The shopkeeper smiled at him and agreed to box up all their spine-candles and have them delivered to the Dark Arts Classroom, Hogwarts Castle, care of Professor Lupin.
Pleased with his first act as a proper Professor, he followed McGonagall out into the late-summer afternoon, and onwards towards the Scholars' Shop, where he could buy a pot of red ink for marking student essays with.