A/N - So, I decided to write a Naruto fanfiction and it somehow ended up a serial killer murder mystery. This is a pretty long story - I've written about 50,000 words already and it's not finished yet, although I think it'll end up somewhere between 60-70K. The chapters are mostly rather long, though (this is a short one at about 4k), so I'll be updating every 2-3 days in an attempt to not catch up with myself too quickly. I hope you enjoy.

The second body was discovered on a Tuesday morning when a concerned customer at the tattoo parlour tried to find out why the owner hadn't opened the shop. He went around the back to the door that led to the upstairs apartment to find the wards down and the door unlocked. Upstairs, he opened the bedroom door and gagged on the smell of blood.

The news travelled fast, and by the afternoon everyone knew that another kunoichi had been murdered in her own bed. Death was usually whispered about in Konoha, the news passed respectfully on and received with stoic grace. It was too common, even in peacetime, to be surprising. But as the name Hyuuga Eri spread from mouth to mouth, the news of her death spilt over into gossip. There was nothing normal about the way she'd died.

Kakashi heard about it when he returned with Team Seven from a particularly muddy D class mission. It was Iruka who told him, as he handed over a mission report covered in dirt. Iruka didn't complain at all about the state of the paper, which was shocking enough for Kakashi to ask him what was wrong.

"Hm?" Iruka looked up from scanning the lines of spiky handwriting. "Sorry, what did you say, Kakashi-san?"

"You're distracted," Kakashi observed. "Did something happen?"

Iruka's eyes widened in understanding. "Of course, you were out all morning, you wouldn't have heard. Hyuuga Eri's been killed. Tied to her bed and stabbed like poor Akane-san."

Fujimoto Akane had been killed eleven days ago. News of her death had gone around much like Eri's, although without the slight edge of hysteria that bordered the whispers now that two shinobi had been murdered within village walls.

Kakashi had never heard of Fujimoto Akane, but Eri's name gave rise to a hazy face: middle aged, a crooked tooth in a wide grin, those unnerving Hyuuga eyes.

"Didn't she own the tattoo shop?"

"That's right. I heard she's the one who inks the ANBU tattoos."

That solidified the memory a little. She had laughed when Kakashi had flinched at the first touch of the needles on his skin. Relax, kid. It's not a weapon unless I make it one.

"Did you know her?" Kakashi asked. It was almost a pointless question. Iruka knew everyone.

Iruka tapped a pen against his bottom lip, frowning. "Only to say hello to in passing. We weren't friends, though I always admired her. I got the impression she was a more than capable shinobi – honestly, I'm surprised something like this happened to her."

Behind Kakashi, the line for the mission desk was getting a little restless at the delay. Kakashi ignored it. Iruka didn't seem to notice, which was further proof that he was affected by the news.

"Naruto's dragging me out later to buy him food," Kakashi said. Iruka looked startled by the change of subject. "You should come with us."

"I'd like to," Iruka started reluctantly, "but my shift doesn't finish until eight."

Kakashi beamed behind his mask. "That's perfect timing. We'll be meeting at Ichiraku."

Iruka reached a hand up to tug nervously on the end of his ponytail. "Are you sure that's not too late?"

"Maa, sensei." Kakashi winked. "It's a date."

Umino Iruka had come to Kakashi's attention years before they'd had Naruto in common, although they hadn't really socialised before Naruto had brought them together. The first time Kakashi became aware of Iruka's existence was the year of Iruka's chuunin exams when Kakashi was nineteen. It was two years after Hyuuga Eri had inked the ANBU tattoo on his arm, and he was one of the masked elite chosen to accompany Sandaime to the chuunin exams, which were being held in Mist. Secretly, Kakashi thought the genin that year were disappointing, and he watched the first two rounds of the exams with disinterest. The rookies all seemed so old and yet so unskilled it was almost embarrassing. Some of them were older than Kakashi, and even the youngest were a good six or seven years older than Kakashi had been when he'd made chuunin.

When Iruka's fight had begun in the tournament round, Kakashi didn't bother to listen for his name. He briefly noted that a Konoha genin was in the ring: a nervous-looking boy, fifteen or sixteen, shorter and slighter than his opponent and definitely less confident. Kakashi didn't even watch the first half of the match. He was too busy eyeballing the other dignitaries and their guards who sat in the private box with Sandaime. After all, he was ostensibly there for his hokage's protection, in case someone was stupid enough to target him while he was outside Konoha.

It was Sandaime's quiet chuckle that brought his attention back to the ring rather than the crackle of lightning or the cheers from the stadium. Kakashi glanced down and for the first time paid attention.

Iruka's opponent was going all out, using an impressive lightning jutsu that Kakashi knew must be burning through his chakra. Iruka had a seal clutched in his hand and was activating a barrier, which didn't waver at the onslaught of electricity. Just as Kakashi thought that Iruka's tactic would be the safe but boring method of waiting out the attack until his opponent was low on chakra, Iruka drew another seal from a pocket with his other hand and, without dropping the barrier, sent a bright flare through the lightning to burst into red sparks in front of his opponent's face.

Later, Kakashi would try, as an experiment, to activate two seals at the same time. He spent an hour on failed attempts until he had to admit that he simply didn't have the chakra control required to keep the first seal active while he focused on his other hand. In the end, he didn't bother to train himself to do it. He was more of a jutsu guy than a seal guy anyway.

Blinded by the flare, Iruka's opponent stopped flinging lightning and instinctively put a hand to his eyes, blinking hard. Kakashi almost winced at how easily he fell for the distraction, coming into a defensive stance too late to avoid Iruka's foot colliding squarely with his face. He hit the floor, and Iruka conjured a shadow clone and passed it something that Kakashi couldn't make out from that angle, and then the other boy was on his feet again, angry but still half blinded and now outnumbered. Iruka's taijutsu proved to be sharp and accurate, if not backed up by the raw strength of the other boy's frame, whose physical advantage was now almost useless.

"It's over," Sandaime said quietly, for Kakashi's ears only. Kakashi frowned, not sure why Sandaime was so sure when there was still ample opportunity for the larger boy to make a comeback, but then Iruka made his final move and Kakashi could only wonder how anyone could have seen it coming.

The real Iruka moved back from the fight, his clone preventing the other boy from following, and then Iruka simply threw a seal, which activated as it hit the ground, creating another barrier to trap the boy and the clone inside it and leaving Iruka standing outside. The fighting stopped, the boy staring warily around him, uncomprehending, and then the clone held up the seal that Iruka had passed it.

"That's an explosive tag powerful enough to blow you to pieces," Iruka said. He turned to the match mediator, who hovered outside the immediate fighting arena. "I'm not going to kill him. Call the match over."

If it was a bluff, it earned points in Kakashi's book for the sheer amount of balls it took to try and bluff through a chuunin exam. The mediator seemed to doubt Iruka too, and after a brief moment of consideration he announced there would be a pause in the fighting for Iruka to prove that he could kill a man with the set up he'd created without also hurting himself.

Iruka let the barrier down and the other boy growled something that Kakashi couldn't hear, his face red with humiliation. And then Iruka set up the barrier around his patiently waiting clone, who set off the exploding tag. The burst of fire filled the small space, dissipating the clone instantly, fire licking the invisible walls and straining against them until Kakashi thought for one awful moment that it would break and Iruka would be consumed by it. And then it was over, and all that was left was an empty barrier full of smoke and scorched ground and the stunned mediator declared Iruka the winner.

Iruka looked up towards the box, eyes scanning the faces until they settled on Kakashi, and he smiled and waved. Only when Sandaime gave a cheerful wave back did Kakashi realise that Iruka wasn't looking at him at all – why would he? The boy didn't even know him – and for some reason he felt almost disappointed.

"How did you know he was going to win?" he asked Sandaime in the break before the next match.

Sandaime graced him with his grandfatherly smile. "Iruka-kun has a very expressive face. It's the same look he gets when he knows he's going to beat me at shogi, like he's just seen the answer to a difficult problem. What did you think of him, Hound?"

"I've never seen anyone win a battle with a barrier," Kakashi said, which didn't exactly answer the question, but was a compliment in its own way.

Sandaime chuckled lightly. "Iruka-kun is very good with seals. Exceptional, really, for his age. I just wish he would put his skills to better use than playing practical jokes on an old man."

It took Kakashi a moment to realise that Iruka was the famed troublemaker of Hokage Tower he'd heard about but never personally fallen victim to.

"He'll never make jounin," he said. "Too little discipline, too little offensive power."

Sandaime shrugged off his bluntness with the ease of practice. "He told me before coming here that he doesn't want to try for jounin. This is as far as he's aiming."

Kakashi really stared at that. What kind of teenager didn't dream of becoming an elite shinobi? Sandaime took out his pipe and lit it, oblivious to or ignoring Kakashi's shock.

"Remind me, what's his name?" Kakashi asked when Sandaime had taken his first puff of the pipe.

"Umino Iruka," Sandaime pronounced with all of the exasperated affection that defined his relationship with Iruka. "Remember it, Hound. He's going to be one hell of a chuunin."

And years later, Kakashi would watch Iruka become the most loved teacher at the Academy, the tyrant of the mission room, the older brother to a boy whose body housed a monster, and those words would come back to him in Sandaime's proud, confident voice. Kakashi watched Iruka smile and shout and flush pink when Kakashi teased him, and he couldn't help but agree with the assessment. Umino Iruka was one hell of a chuunin.

When Iruka came off shift ten minutes late, he found Kakashi waiting for him in the corridor outside the mission room. He was leaning against the wall, face buried in a luridly coloured paperback, which he didn't immediately stop reading when Iruka stopped, surprised, in the doorway.

"Did you think I was going to stand you up?" Iruka asked, torn between amusement and exasperation.

Kakashi's single visible eye finished scanning a particularly riveting paragraph and he memorised the page number and slipped the book into his vest pocket, finally looking up to smile at Iruka, the expression somehow still clear despite the mask covering half his face. "Maa, I'd never expect something so low of you, Iruka-sensei. I decided to be a gentleman and walk you down to Ichiraku."

Iruka snorted, but couldn't help the twitch of his lips. He turned to head out of the building, Kakashi trailing half a step behind. "Thanks for the thought, but I don't need chivalry."

Kakashi hummed in agreement. "But it's nice to be offered."

When they reached the ramen stand, a good hour and a half after the time Kakashi had told his team to meet them, he was actually impressed to see that the three genin were standing in the street, waiting impatiently. If he'd been in their shoes he would at least have ordered food by this time. He'd tried to make a bet with Iruka some weeks ago on how long it would take before the kids started turning up to training sessions on time (according to Kakashi's schedule, that is, rather than the times he told them to turn up. To give them a sporting chance, he'd even started a pattern: Mondays were an hour late, Tuesdays an hour and a half, Wednesdays a mere forty-five minutes...). Iruka had refused to place a bet and had even had the audacity to scold Kakashi, as though he were in the wrong rather than the brats who couldn't even grasp basic pattern recognition.

"You're late," Sakura accused when she spotted him, her chest puffing with indignation.

"Where have you been?" Naruto whined, clutching his stomach with an expression of agony. "I'm so hungry I think I'm dying."

Unmoved by this display of outraged suffering, Kakashi shooed them towards the row of stools at the counter. They seriously expected food and punctuality? Kids today were so demanding.

It was Sasuke who eventually brought up the murders. He'd been quiet for most of the meal, but that wasn't unusual, so Kakashi was surprised when he looked up and asked, "Should we be worried about that serial killer?"

The question had been directed at Kakashi, but it was enough to quiet Naruto and Sakura, and it was Iruka who spoke up first.

"What makes you think it's a serial killer?"

"That's what people have been saying," Sasuke said. "They're calling him The 3am Killer because he comes for you in the middle of the night. I heard he stabs them in their beds and leaves them to bleed out." His eyes gravitated back to Kakashi again. "That's not a normal way to kill someone."

Kakashi could hear the unspoken logic. Leaving an enemy to bleed to death is inefficient. Attacking an enemy in their own territory is risky. No right-minded shinobi would choose to kill that way.

"I think there need to be three victims to call it a serial killer," he said, which maybe wasn't a helpful comment judging by the look Iruka shot him.

"Does that mean he's gonna kill other people?" Naruto asked in a small voice. Definitely not helpful.

Iruka lightly bit his lower lip. Kakashi knew the struggle he was facing: he wanted to be comforting, but he didn't want to lie. "I hope not," Iruka eventually settled for. "And I'm sure the three of you don't have to worry about anything, but you should all make sure you lock up properly at night and don't forget to set your wards. If you don't feel safe, Naruto, you can always stay at my place." He turned to Sasuke. "That goes for you too."

"ANBU is investigating as we speak," Kakashi added. "Hopefully they'll catch this guy before he can hurt anyone else. He might not even have any more victims in mind. We don't know enough yet to guess why Fujimoto-san and Eri-san were killed."

The three genin considered this, and Kakashi met Iruka's eye. A silent conversation passed between them, and then Kakashi turned away and idly mentioned how well Sasuke had performed on their mission that morning, which sparked the anticipated flare of Naruto's competitive streak, and even though Sasuke gave Kakashi a flat look indicating that he knew full well what he was doing, the topic wasn't raised again.

Tenzou sat on the floor of his apartment, blown up photographs and pages of notes spread out over the low coffee table and carpet around him. He leaned back against the sofa and sighed, scratching the stubble starting to itch at his jaw. To his left was everything he had that was related to the murder of Fujimoto Akane; to the right, Hyuuga Eri. In the middle he'd placed a sheet of lined paper torn from a notebook, which was blank except for the question written in black ink in the centre: Why them?

The trouble was that no matter how much he scoured over the information he'd collected so far, he couldn't find a connection between the two victims. All he could say was that both were chuunin-ranked shinobi and both were female and both had been killed in the same way. The wards at both houses had been down, although it wasn't clear whether they'd been skilfully disabled or whether the victims had let their killer in, and the women had both been found lying on their backs, stabbed through the stomach so forcefully that the weapon had penetrated their backs as well, impaling them. The killer had taken the murder weapon with him, but it was probably a short sword, judging by the size of the wounds in the victims' bodies and the depth of the holes stabbed through the mattress. Cause of death had been blood loss: a slow, agonising way to die. The victims' hands had been bound to their bed frames with chakra wire, and the bruises on their wrists suggested they had been conscious as they'd bled out, but if they'd called for help it had been in vain. There had been seals in the rooms that blocked noise or chakra flares from penetrating the walls.

The 3am Killer they were calling him now, less than a day after his second victim's body was found. It wasn't even accurate. The medic who had examined the bodies had estimated time of death at about 2am for both women. They had bled out in less than twenty minutes.

Tenzou picked up two of the photos. Not the crime scene shots, but pictures of the victims when they'd been alive, both smiling at the camera, healthy, happy, unaware that they were going to be murdered. They were chuunin and they were female. What else? There must have been something else.

Akane had been twenty-seven; Eri fifty-one. Akane was close to her parents and sister and had a long-term boyfriend; Eri had been all but disowned by her family and hadn't held a steady relationship for years. Akane was from a humble background: father a civilian, mother a chuunin; Eri was from a branch house of the Hyuuga clan and had inherited their bloodline limit. Akane was an archivist at the Hokage Tower; Eri was a tattooist.

Neither women had been sexually assaulted, and there was no sign of a struggle in either apartment. So far, Tenzou hadn't been able to find evidence that they had known each other or had any friends in common. Akane didn't have any tattoos and Eri hadn't signed anything out of the archives in over three months. They'd never been on a mission together. No matter what angle Tenzou approached it from, he couldn't find a connection between these two strangers who had both been killed, in all probability, by the same person.

Of course, he'd entertained the possibility that the second murder was a copycat, but Tenzou thought this was unlikely. He glanced around until he located a manila folder and leafed through it until he came across a photograph of the seal that had chakra-proofed the room, making it impossible for even the strongest chakra flare of distress to be sensed outside the killing ground. They'd had to track down a specialist to discover what it was – Tenzou had been surprised to learn that Umino Iruka, who he'd known vaguely as a teacher and mission desk worker, was also one of Konoha's leading experts on seals – and a little research had revealed it to be on a list of forbidden seals locked away in the archives. It was amazing that even one person knew how to use it; the idea of a copycat killer also having access to restricted knowledge was unthinkable. Besides, there were details of Akane's murder that hadn't made it out of the ANBU offices but were fully replicated in Eri's death. Tenzou had no doubts that the same person had killed both women.

Among the sheets of paper strewn over his living room floor, the ones that Tenzou's eyes kept coming back to were the photographs of the victims as they'd been found. It was something about the pale skin against the dark red stains on the sheets beneath them. He didn't mean to stare at them, but whenever he blinked himself out of his thoughts his gaze would be burning a hole through the images.

Eventually, Tenzou put everything back into the folders and sealed them in a scroll, the sort that would self destruct if anyone apart from him tried to open it. It wouldn't do to leave ANBU investigation materials lying around his apartment, no matter how secure his wards were. He stood up and stretched, popping his shoulders, and then turned the light off before padding through to the bathroom. Between brushing his teeth and climbing into bed, he double checked his wards and the locks on his doors and windows, even though locks and walls had long since ceased to make him feel safe. Being ANBU did that to a shinobi.

As he lay beneath the light sheet he slept under now that it was almost summer, Tenzou rolled onto his back and pulled his shirt up just enough to press a finger into the soft flesh of his stomach, and further, into the hard muscles beneath. He stared at the shadows on the ceiling and imagined that his finger was a sword and that he could feel the blood pumping slowly into the sheets below him, seeping down into the mattress, killing him by inches. He felt his pulse flutter in his finger and drew his hand away, shuddering. When he curled onto his side, facing the window because that was another thing being ANBU did to a shinobi, the sheet covering him felt flimsy and insubstantial.

Chuunin and female. He saw their faces in his dreams.