Day 11 of a Holloween challenge I did over on AO3 that I thought you guys might enjoy !

It's rated T, but beware there is some blood. Nothing graphic but there you go.

There was a tattoo on his boyfriends arm.

Now, Law had a lot of tattoos himself. On his knuckles, on his arms, on his back and chest. Most of his skin was covered in some kind of ink. So it was not the tattoo existing that was unusually to him or that drew his attention. Instead, it was the fact that he could never tell what it was.

It was the moon. That much he was sure of. But he was never one hundred percent sure what phase it was in. He thought it was half full, or half empty, or a crescent.

Sometimes it looked almost new, sometimes it was a breath from full.

It took him a long time to admit to what he was seeing. At first, he passed if off as nothing more than a figment of his imagination. When they first met it was first day of june, a bar fight. He didn't know who it was that was covered in red, he didn't know the wild gold eyes and the painted mouth split into a grin that bordered on feral, but as he stood above the beaten bodies Law couldn't help picking his way across the ruined room and introducing himself. As a doctor, just interested in seeing to his wounds, of course.

When they kissed it was all teeth and bruises and nails that dragged through skin. Law gave as good as he got and a pattern developed.

The first day, he thought the moon was a waning crescent sitting on the hard lines of Kidd's wrist. There was nothing about him that was soft, nothing about him that spoke of kindness or gentle inclinations. That was half of what drew Law to him. His vicious body and his mean streak, a mile and a half wide. After that it was his grim humor, matching up with Law's in a way that no one else's quite did. There wit's matched, their bodies slot together and before he knew it Law was in deep.

Too deep.

But back to the tattoo. The next time they met, the crescent was reversed, and bigger. Law dismissed it. He dismissed it a lot, as a trick of the light. Then he started taking pictures. Selfies, mostly, nothing that would get Kidd's face in it. Eustace had an aversion to photographs.

The tattoo changed.

Law checked. It matched the phases of the moon perfectly.

Trafalgar D. Water Law was not a man of superstition. He didn't believe in monsters under the bed or fairy rings or magic spells. He believed in reason and logic, and the scientific process.

And so, it began.

Slowly, at first, Law started marking his suspicions.

He checked out library books, asked tattoo artists and spent hours online. The general consensus was that he was dating a werewolf, or crazy. Law was pretty sure he wasn't crazy. Not in that way, at least. He was also pretty sure werewolves didn't exist.

Which did not explain why he had twenty four tabs open on werewolf lore and a baker's dozen books on the same subject sitting around his house.

He always made sure to hide them when he was going to see Kidd. There was never any telling where they would end up at the end of the night. Whose place, who's bed, who's dining room table. Against who's window.

The biggest proof he found was when Kidd sliced his arm open working in his shop and by the time Law was able to get a look at it, beyond Kidd's fussing and arguments, it was too shallow and too small to warrant the amount of blood on his clothes.

Even after all of his research and the creeping suspicion that he was dating a monster of a different sort than he'd thought, Law still texted him the time to come to dinner and set the table. It was, technically, their anniversary, but neither of them were the type to celebrate that kind of thing. So he didn't go all out or light candles.

He laid out dinner, pannfisch on a bed of cabbage, set the table and waited.

Law wondered sometimes what Kidd thought of his apartment. It was vast opposition to the adjoining house stuck to a workshop, that he shared with a blond that Law had never seen in more than passing. Contrary to the cluttered house that smelled distinctly of oil and copper and pine, Law's upscale apartment was straight lined and new furniture. It wasn't lived in, it was pristine and sensible. Fine but not excessively so.

Law was a top surgeon. He could afford anything, but there was no point in spending money on a place where he rarely even was. The hospital took up most of his time.

Kidd took up the rest.

No one knocked on the door and it didn't squeak but Law knew that Kidd had come in. He filled the room just by being in it, his presence inescapable and massive. Lesser men would bow beneath it, but Law thrived within it, fighting and grasping and sometimes even laughing, just with the thrill of it. Kidd reminded him he was alive.

He didn't turn when he felt the heat of Kidd's bulk buffer against him. Law always felt cold. Cold and still, his hands steady no matter what he was doing. Surgeons hands.

Kidd ignited a churning ember under his ribs, a lick of fire in his stomach.

He looked over his shoulder, mouth spread in a challenging flash of teeth.

"You're late."

"Fuck you," Kidd poked him in the small of his back. "Let's eat."

"You have no manners. What were you raised by wolves?"

Law ignored the thrill that shot through his head and made his fingertips tingle when Kidd's broad shoulders brew together and his cheek twitches in something that broke his cocky grin.

His eyes, a gold that Law had never witnessed in humans before, narrowed minutely at him. Law met them head on, waiting. Kidd, as always, ran out of patience first.

"You're just as bad. I thought doctors had bedside manner, but you're just an asshole."

"I'm a surgeon," he said dryly. "My patients are all unconscious. If they're lucky. If they aren't they get to listen to my music."

"You have shitty taste in music," Kidd said frankly.

"I'm surprised you can hear anything with the crap you blast. Sit your ass down, Eustass."

A thrill shot up his spine when Kidd bared his teeth and took a threatening step towards him. "Don't call me that."

Law lifted his middle finger between them. "Shut up and eat your cabbage."

Kidd moved to shoulder past him and sat at the table petulantly. Law sat across from him and started in on the fish, and for a minute he wondered if Kidd's pride would override his stomach. Kidd gave in at last and picked up a fork.

He howled and dropped it immediately, gripping his hand to his chest. Law's head snapped up to stare at him with wide eyes. Steam came off of Kidd's hand in waves, billowing up. A feral glow, pain and anger, burning in his eyes.

Law stood, dropping his fork and knife and moving to Kidd's side in one long stride. He shoved his hand in front of Kidd.

"Let me see," he ordered shortly.

"Fuck you," Kidd said promptly.

"Let me see," he said again. Kidd hadn't been kidding about his bedside manner. Law struggled to soften himself. "I'm a doctor. Let me see, Kidd."

Kidd eyed him distrustfully for a long, long time before he finally turned over his hand. The steam had finally settled, but what was left was lines of charred skin where the fork had touched him. That didn't make sense, though. What would the fork-

Silver. It was silver.

Law opened Kidd's fingers slowly, taking stock. There was two stripes of dead skin on the outside edge of the pointer finger and two matching strips that touched the middle and forefinger together. The pad of his thumb and one knuckle were the same.

"How does it feel?"

"How the fuck do you think? It hurts!"

"Good. Then you still have nerves. That means it looks worse than it is. Don't punch me."

Law brushed his thumb across Kidd's burn skin. His new 'patient' snarled. He didn't sound human. Law ignored him. He could feel under the dead skin something pushing up. It pulsed with Kidd's heartbeat.

"What's the prognosis?"

"That you watch to many hospital drama's. The diagnosis is that it's a third degree burn. You'll need a skin graft. At the hospital."

"Hell no!" Kidd yanked his hand away. Law let him, watching the regret when he bumped the burns together and the pain struck again. If he felt the pain that much, it would only be the top couple of layers that were dead, and beneath that the skin was alive. Good for Kidd. Good enough that, maybe, if they did it right…

"You need to come with me to the hospital so we can treat it. If that gets infected, you'll be in trouble. I'll do everything, but I'm not properly equipped here for it," Law spoke slowly, with more patience than he normally allotted a stubborn patient.

"I'm not going to a hospital. Fix me here," Kid moved to cross his arms stubbornly before he thought better of it and glared. The thrill that came from the glare before was gone. Law was all business now. He frowned.

He couldn't force someone, especially not someone of Kidd's size and temperament, to submit themselves to real medical care. Why did he have such stubborn people in his life?

He really shouldn't. But, Law thought of the accident weeks ago. The cut on his arm, the blood, bright as his hair, too much for what Law found. He'd never gone to a hospital then, either. Law stared hard at him.

"It still might get infected and you'll be in a lot of trouble." Law could lose his license. This was a stupid idea.

Kidd looked straight at him.

"Do it."

Law took him to the bathroom and fetched his doctors bag. He didn't use it often, but his instruments were sharp and well cared for. The white leather was cool as he slid his fingers across it and undid the padlock. He flipped the lid open and got started. He cleaned his hands with alcohol gel and pulled on sterile gloves. While he worked he talked, going over the basics. Height, weight, allergens, medical history, past addictions.

He held Kidd's hand still when he pushed a needle with barely any diamorphine in it under the skin. Working with mental math and the wrong equipment made his skin crawl .It was sloppy and unprofessional.

Law picked up a pair of small scissors.

"Look at the ceiling," he told Kidd, and got started. Kidd kept twitching while Law was entirely sure and steady. He held his fingers steady while he cut away the dead skin. Like he thought, it wasn't as deep as it looked. Fluid seeped sluggishly from the wound.

Law was quick about disinfecting it and laying a thin layer of plastic over the open flesh before he wrapped it in tape. To an outside it looked professional. To a renown perfectionist it was a mess. Law's fingers itched with the desire to replace the damaged flesh with new, living skin and properly neutralize the potential infection.

Law pushed Kid's sleeve up until he could see the moon that painted, nearly full, on his wrist. He felt the muscles tense under his hold. Almost full. Another night. Silver burns and gold eyes.

Law looked up and stared straight into the eyes of a wolf.

"Busy tomorrow night?"