Disclaimer: Naruto and its characters are the property of Masashi Kishimoto

It was the spring after Orochimaru's death, when three Konoha ninja found the last of the secret laboratories.

They found it at the base of an old umbrella pine. The entrance had been sealed with rocks and filled with pine needles, and it was almost lost in a thicket of red bracken, but almost was not good enough for three Konoha ninja already excited by the prospect of returning home, and eager to finish their job.

"Are you sure this is it?" Gobo brushed away the charred bracken from the rocks and thanked his lucky stars he was wearing his gloves. The stones were hot from the katon jutsu Ninjin had used to clear the bracken.

"No doubt about it." Ninjin lifted a rock from the entrance and wrinkled her nose. "Smell that? It smells like all the rest of them."

Gobo sniffed tentatively and immediately recoiled. The cold wisp of air floating up from the hole was sharp with ammonia and the bittersweetness of chlorine. His nose stung, and as Daikon and Ninjin continued to shift rocks from the entrance the smell grew, and grew more textured – there was an undertone of mildew, a top note of something fruity, and shot throughout something acrid and poisonous.

"Here goes the fun part," said Daikon, his smile typically dry.

He dropped the lantern down the entrance. It landed on the floor below with a clatter and fell on its side.

They held their breath and waited, straining their eyes for signs of movement in the dark.

"Nothing," decided Gobo, after listening to his heart drum in his ears for three minutes.

"Nothing," agreed Ninjin, "but be careful."

They levered themselves down the entrance and Daikon picked up the lantern. They walked down the corridor of the complex in silence. It was small compared to other laboratories they had seen, which was a good sign. It meant there was not enough room to house large experimental subjects, at least not more than one or two. Another team sent by Konoha to a cave in the west had found thirty or so subjects lying in their own blood, and not all of them had been dead. Gobo, Ninjin and Daikon had been lucky so far.

Ninjin opened the first door they came to with a gentle push of her fingertips. When nothing was triggered, they moved in. Gobo was mildly surprised. He had been expecting a surgical theatre, a rack of sharp-toothed instruments on the walls, but this was more like an intensive care unit for a single patient. A bed took up the centre, with the corners of its sheets turned down, and it was surrounded by screens and machines and bunches of tubes. Gobo had done his stint as a practical medic-nin before switching to research. He recognised life support and dialysis machines when he saw them.

"Daikon, you stay here and take stock of the equipment. Gobo, let's move on the next room," Ninjin said briskly. She lit an old torch in the bracket before leaving.

Apart from a bathroom, (Gobo wondered how Orochimaru had managed the plumbing) there were three more rooms in the complex. One was a store cupboard which he left to Ninjin, because he couldn't stay there without his stomach heaving. The next was a lab bench, with a rack of staining chemicals, an incubator and no doubt microscopes packed away in the cupboards. The last was a study. Gobo stopped there. He was here to collect up research papers that Orochimaru had written. As mad as the man was, he had been a genius scientist and his research would be invaluable to Konoha medicine if they could get hold of it. Kusagakure had been making moves to demand papers as compensation for their genin who had been killed in the chuunin exams.

He was filling his bag with the contents of one of the filing cabinets when Gobo heard a breaking of glass. It had come from the store room.

"Ninjin!" he cried, sliding into the doorway and covering his face with a mask against the smell. "What's happened?"

"It's alright!" Ninjin held up her hands. "I was just checking what was in this case and dropped one of the vials. No need to worry."

Gobo shivered. The temperature in the store cupboard was well below any of the other rooms. Perhaps there was some sort of seal in action, withdrawing heat from the air. "This is Orochimaru's laboratory. Of course I'm worried."

She scowled at him but bent down to the floor to pick through the glass. He crouched down beside her. There was a cap with a label, the stroke of the number already bleeding purple out of black. "One?" he read.

"They're numbered up to ten," Ninjin said, glancing through the case of vials again. She pulled out another one and peered into its cloudy contents. "Stab vials. He's storing bacteria in them."

"What kind?" asked Gobo.

"You think my eyes are microscopes? How the heck would I know?"

"Are you two ready to go?" called Daikon, bending his head round the doorway.

Ninjin wiped her hand across her face and sneezed. "Almost." She packed the rest of the vials into her bag. Gobo went back to the filing cabinet, trying to crush the feeling that something had just been done, that something had just been committed, and to convince himself that the chill running down his back was the air from the refridgerated storage room and not cold sweat.

When the last of the folders and files were strapped to the sleigh, Ninjin, Daikon and Gobo began to make their way back to Konoha, the entrance to the laboratory sealed once again, against rogue ninjas who might plunder it, and wild animals who might be tempted by the smell of decay.

Ten days after their return, Gobo was in his hospital office. He was still trawling through Orochimaru and Kabuto's papers, sorting through for projects that were within the Konoha ethical code of conduct to continue. There were, surprisingly, quite a lot. Orochimaru and Kabuto had both had their scientific training in Konoha and their educational background was clear in the meticulous precision of their methods and their sourcing of resources. Orochimaru's papers said that his subjects were all either volunteers or death row prisoners, sold to him by the other nations in exchange for the results coming out of his laboratories. In that respect, Gobo was sad to admit, Konoha wasn't all that different.

He adjusted the mask around his nose and mouth and coughed gently. It was early in the morning. There was nobody in the office yet, apart from himself. Truth be told, he wished he was still in bed. He had been feeling very out of sorts lately. Every so often he would break out into a fit of coughs, and in the past few days those fits had become heavy and wet with mucus. His limbs felt heavy too, heavy and even a little painful. His joints ached when he did even the more basic exercises in their ninja fitness regime and he was finding it increasingly difficult to write. It wasn't his grip that was losing strength. His extremities were going numb. Sometimes he had to check to make sure his toes were still there. It was a terrible case of flu, if ever there was one!

He hid it well though, Gobo told himself, as he proceeded through the stack of papers. As a ninja, hiding pain was trained into them as a survival skill.

The door opened behind him. "Gobo." It was Daikon, pulling down his face mask with a cough. He'd come down with a cold. His face was pale. "I need to talk to you. What did Ninjin do in that store room at Laboratory Number Twenty Nine? She broke a vial, didn't she?"

A twist of fear clenched Gobo's guts. "What's happened to her?"

"She started coughing up blood in her office. They've taken her to Ward 12."

Ward 12 for unknown infectious diseases, a hurried, trembling voice informed Gobo, somewhere in the depths of his brain. Ward 12. Gobo's hands were trembling. He couldn't feel his fingers, so he set down his pen. "I knew it," Gobo gasped, pulling off his glasses to rub his eyes, "I knew this was going to come back to bite us. Somehow, I just knew – "

Nervous laughter bubbled up from inside him and Daikon reached across to put a hand on Gobo's shoulder. "Hey, Gobo, calm down, man – "

The nervous laughter changed to a thick, hacking cough, and the next instant Gobo was starkly aware of something wet and slippery lodged at the back of his throat. His mouth tasted salt, a mineral quality like iron or copper, and then his hands and the paper in front of him, were dripping with blood.

Daikon's hand flew off Gobo's shoulder.

Gobo was dimly aware of Daikon locking the door of the office. There was a dull ringing in his ears, a pressure behind his eyes. He held his hands in front of him with his spoonful-worth of blood cupped in their palms, and stared.

Daikon was dialling a number on the internal communications system. "This is Office 306," he was saying into the device, "one medic-nin showing the same symptoms as Nemoto Ninjin, request assistance to transport to Ward 12 with full hazard precautions, and – "Daikon coughed, loud and thick, and he paused, suddenly very silent. "Make that two medic-nin showing the same symptoms as Nemoto Ninjin. We are isolated together in Office 306. Thank you."

He switched off the device and turned back to Gobo. There was blood running from the corner of Daikon's mouth, turned up in a painful, nervous smile. "Help's on it's way," he said. "We should wash our hands."

But three days later, Nemoto Ninjin, Hijiki Gobo and Tsukemono Daikon were already dead, and their beds in Ward 12 were filled with another round of patients, checked in for a strange and unknown illness spreading rapidly through Konoha.

They called it the Mottled Cough and the Snake Death. It was the spring of Kimimaro's Plague.

Author's Notes: This is set in an alternate timestream where Pain hasn't destroyed Konoha. Thank you so much for reading this prologue chapter and bearing with these characters - we'll be back with all our favourite and familiar characters next time. I didn't want anybody we knew dying here. Having written a one shot, and a short collection of drabbles, this is my first attempt at a longer story. Thank you for dropping by. Please let me know what you think.