A/N: Second season Darker than Black actually has as canon that Contractor and Doll powers originate at the spiritual level. I'm taking that element and ignoring the rest of season 2. (It was mindscrewy. And OOC was everywhere. And the end was... never mind. What season 2?) DtB, season 1. For Bleach - sometime after Zennosuke Kurumadani comes to Karakura, sometime before the Butterfly of Doom.

Thump.

"What we need," Ichigo grumped, stepping back to eye the limp black-clad lump he'd dropped on Karin's clinic table, "is a vaccine against stupidity."

"Too late," Karin observed dryly, eyeing Afro-shinigami's gravity-defying hair as Kuruma-whoever-he-was twitched on the paper. It looked even poofier than normal. She hadn't thought that was possible. "What happened to him?"

"Not sure I want to know." Her brother folded his arms, scowling. "I found him in a dumpster."

That might explain some of the odder stains on the black shihakusho. But there was a depth to her brother's frown that said something was actually bothering him. "Yeah?" Karin prompted.

"Looked like he'd been dropped."

Oh.

And now she was worried. Shinigami were invisible... well, to most people. Or maybe just most people outside Karakura... anyway. Only another spirit should have been able to drop a shinigami. Kuruma-idiot was officially assigned here, the rest of the Gotei 13 shouldn't have bothered him. A ghost would have been too scared or glad to see a shinigami to try to attack him. Her brother's friends were too exasperated by the guy to even bother beating him up. And a Hollow that'd gotten its claws on Karakura's spirit-patroller should have eaten him.

So what happened?

"Visored..."

When she was in the clinic, Karin was a nurse. No matter how annoying the patient. "Take it slow," she directed, catching the guy's less-stained shoulder as he wobbled toward sitting up. "You look like you got a bad shock."

"Lightning kido-?" Afro was muttering. Blinked, and focused on her brother. "There was a Visored!" One of his hands trembled, like a leftover shot of adrenaline. "Only... sort of different? Like something was painted on the mask - and then when I challenged him there was a whoosh and he was gone and- there was a zap?"

"Uh-huh." Ichigo was one scowl away from rolling his eyes. "A Visored who didn't just swat you flat with reiatsu and shunpo away before you even saw him. Sure there was."

Karin watched blue spark between coiling hairs, and wondered if the shinigami had actually taken a header into the power lines.

One hour earlier...

"Why do they run?" Mao's exasperated sigh echoed through Hei's earpiece. Violet eyes gleamed in the night, the only part of the black cat visible as he gazed down into the night-dark alley. "Why do they even bother running?"

Rifling through the Yakuza body's pockets, Hei extracted the stolen flash drive. He didn't bother to shrug. Why the dead man had headed for Karakura, who knew. Outside of criminal hope springing eternal; low-level Yakuza never did seem to grasp the extent of the Syndicate's reach.

"Well, scratch that rumor," Mao hmphed, eyes half-closed in relief. "For once, let's have a nice, quiet end to a mission."

"Patrol officer walking the main street." Yin's voice, calm as moonlight. "Two minutes."

Plenty of time. Hei took a step back and ran up the alley wall, gaining enough height to flip over onto Mao's roof and run.

The cat ran with him, footfalls just as silent. "I bet you're wondering what rumor."

Behind the mask, Hei felt the whisper of an urge to sigh. "No."

"For a Contractor, you're a horrible liar. This one'll make even you laugh."

"I doubt it."

A hairball-hack of a chuckle. "Seriously. Somehow the Yakuza got it into their tattooed heads that - get this - Contractors can't come into Karakura."

"...What."

"You didn't think about telling us this before?" Huang's voice broke into the radio, gruff and probably longing for another cigarette. "What if they'd been right?"

"Are you kidding me? Contractors go wherever we want to. That's the advantage of being rational, unlike you crazy humans." Mao sniffed, cat-haughty. "Besides, if you'd read the rumors you'd have broken a rib laughing, and that might have impaired the mission." He coiled and sprang, clearing the gap between two buildings in one inky leap. "A demon-track from Hell's Gate. Ground zero for the second coming of Mothra. A doorway to Hell and monsters only ghost fanatics could believe in. Nothing even remotely scientific- Uh-oh."

A violet glance and a prickling on his neck were all Hei had to go on. For the Black Reaper, it was enough.

Sway back and sideways, where-?

Nothing he could see. But the faint whistle of air, riffling his hair askew from his own motion-

Invisible blade. Force-blade, or invisible attacker?

Mao danced clear of his feet, black fur bristled. "He has a katana!"

Seriously?

But that and the pressure of air gave Hei the shape of his enemy's movements.

Not as versatile as a knife, if I get inside his range, where are his feet- there!

A tremor under his soft-soled shoes. The kind that came from an idiot not familiar with roof-walking stomping carelessly on unsupported shingles, not the underlying joists.

Weight shifting back; lifting sword for overhand strike, vision will be blocked in-

Hei ghost-stepped aside and behind, hidden in the blind spot of his enemy's own sword. Breathed out, calling on his power, hand snapping closed on a sweaty throat.

Whoever you are... you're between me and extraction.

This is not your lucky night.

The rooftop burned blue.

The limp thump was all too familiar; the result of enough voltage delivered to a living brain to put down three humans or one Contractor.

The fact that whoever he'd electrocuted was still invisible, wasn't.

"You didn't." Mao was half-hidden in the roof's shadows, purple eyes blinking wide as a startled cat's could. "You... oh, you would."

Hei crouched, running his fingers over invisible cloth and skin to determine if another shock was necessary. Contractor powers ended with death. If his opponent was still invisible, odds were he was still alive. "Do you know him?"

Mao had a sudden coughing fit. "No, no, never seen him before in my life... did you scramble his brain enough to cloud our trail?"

"Yes." That part of his power, he knew well. Every living brain ran on electricity. Whoever he'd taken down shouldn't remember anything for the past hour, maybe two-

Gloved fingers met a wooly mass. Hei traced the sphere of ridiculous floof, face growing even more blank behind the mask. No wonder this Contractor was running around invisible. Who'd want to be caught dead looking like that?

Speaking of. "You can see him?"

"Well. Cat." Mao gave a black ripple of a shrug. "Vision in this body isn't quite the same... what are you doing?"

Two steps left, two right, shifting his feet just above the shingles-

Hei's toes hit the hilt.

He picked it up, ignoring Mao's sputter, squinting at what looked like empty air. He could feel the heft in his hands. Hear the faintest whistle, as the razor edge split the wind... and who on earth put that sharp an edge on a killing blade, honestly, you'd just break it the first time you hit bone.

He was not inwardly gleeing over an invisible sword. No. Contractors might rationally consider the advantage of an unseen weapon. They did not glee.

"Ah." Mao sat back on his haunches, tail-tip flicking. "I don't think it likes you."

Hei eyed him askance. "Have you ever heard of a Contractor able to possess objects?"

"I've never heard of one, no."

We're the Syndicate's pawns. We only know what they want us to know.

Not worth the risk. Hei glanced over the edge of the roof; no point in impaling a hapless passerby with a sword they'd never see coming.

Dumpster. Perfect.

"You just..." Mao blinked as invisible steel clattered down. Then buried his face in his paws as Hei hefted up limp cloth and flesh to follow after.

Clang-clatter-whump!

"Missed the sword," Hei observed.

"How do you know that?" Mao's words were muffled by fur.

Hei tilted his head at the disbelieving cat. After all the years he'd used knives? He knew what steel in flesh sounded like-

And... he knew this sound. A sort of hitching hiccup, with the faintest hints of a too-old-for-kitten trill.

That was not Mao bewailing his fate of being stuck with an independent doll, an ugly ex-cop, and the most irrational Contractor on the face of the planet. That was Mao laughing hysterically.

...I am not getting paid enough for this.

"The officer is passing," Yin reported. "He hasn't seen you."

Hei raised brows behind his mask, struck by a sudden thought. "He will."

"Ah, come on," Huang growled, "he's not part of the assignment-"

"Exactly." With a last glance at the dumpster, Hei scooped up giggling fur, racing silent across the rooftops. "Yin. Tell me when I'm three minutes ahead of him."

"Yes."

A few minutes' run under the starlight, and Yin gave him the mark.

Now.

Swing down and silent, landing quieter than the cat still snickering under his arm. Slip the gear bag out from under his coat, tuck Mao into one half of it, and use the other to... go against instinct.

Coat off. Knives off. Harness off. Mask off.

Training let him tuck them all away, and shake out a thin green rain-jacket to cover the tight black top. Dark pants would pass, and the shoes were unremarkable if you weren't an expert. A patrol officer wouldn't be. Not outside Tokyo proper.

Hei plucked up startled fur, voice low. "Play lost cat. Lost pet."

Mao coughed, shocked out of his snickers. "Why?"

"Because we don't know if he was alone."

"Urk," Mao managed. "Mew?"

Bag slung across one shoulder like a good broke college student, Hei reeled back out of the alley-

Just in time to almost trip into the patrolman, and then fall backwards; landing on the sidewalk, eyes wide, arms around black fur as if he'd protect it from everything in the world. "Oh! I'm sorry, so sorry, I didn't see you. I was looking for my Kuro, he got loose... um."

Doubt warred with bemusement on the older man's face. "You were looking for your cat? At night? In Karakura? What's your name?"

"Nanashi. Nanashi Kuroda," Hei said innocently, levering himself up like everything ached. Better not to leave any traces that would connect back to Li Shengshun. Just in case. "I'm a part-time worker over in Tokyo, and, well, I know it's night, but cats." He blinked. "What's wrong with that? I thought this was just a little town. Is there a problem?"

The patrolman opened his mouth... then looked behind him. And winced.

Faking a startled jump, Hei looked that way. Nothing.

...Nothing, that Mao was carefully not looking at.

"Sometimes we have a little Yakuza problem." The officer wasn't quite looking all the way at him. "And sometimes... they run into something worse."

Hei widened his eyes, not rising to that bait. "Yakuza? Oh, no - I should get home, my landlady will kill me..." Why is he looking at my cat-?

A cold chill traced down his spine. He's looking where Mao is looking. He's trying to see if I see what Mao's seeing. Another Contractor?

It was the most rational explanation; the invisible Contractor's partner, in a stolen cop's uniform. Yet Mao was relaxed in his arms, almost purring.

"You get on home, son," the patrolman said kindly. "Keep that cat out of any more trouble."

"Thank you, Officer." Hei bowed as best as Li could with an armful of cat. "I hope you have a good night." One step away, two-

"Oh, and Mr. Nanashi?"

Pocketknife palmed, Hei drew up short. "Sir?"

"If that cat starts yowling like hell... get to lights. And people. Karakura's not safe after dark."

Hei let his shoulders stiffen, then nodded hastily, and started jogging down the sidewalk.

"He has no idea," Mao murmured, far too low for anyone without their radios to hear. "Well. About half of it."

"I better hear about the other half," Huang growled.

"You don't want to. Believe me."

"Later," Hei cut in to what threatened to be a long if quiet argument. "Huang. Sooner we're out of here, the better. Pickup?"

"I should make you two walk home."

"No, he's right; we should stop pushing our luck." Mao gave his reluctant transport a fanged grin. "After all, it's not every night Death has a near-Hei experience."

Dead silence on the radio.

"That's it," Huang grumbled. "After we get back to Tokyo, I'm cutting off the catnip."

A/N: Folklore says cats can see ghosts. The poor patrolman is one of those random Karakura bystanders who's suffered enough reiatsu backwash to also see ghosts. Like a hapless confused Yakuza who has no idea what killed him, it happened so fast...

Mao is a possessing spirit yet apparently at no risk of Hollowification. DtB canon is that a Contractor's star falls when they die. Mao's has never fallen, despite losing his original human body. So I say he's effectively a living ghost, Chain of Fate perfectly fine.

Crossing these two settings is a bit tricky. Bleach physics runs on Rule of Cool. Darker than Black physics are cool because they are as realistic as possible... so characters who can, for example, levitate, have to tackle actual problems like gravity and wind direction. It's DtB canon that Hei is the fastest Contractor. Which should put him into the category of superhuman speed... on the very, very low end of what a trained shinigami is capable of. Hei is no supernatural powerhouse. Up against even a seated officer of the Gotei 13, he'd probably be toast.

...Unless, of course, they did something stupid. Like miss the fact that Hei never really fights alone. He has a team.