Finally the last of the lab technicians had left for the night. Their assistance had been invaluable, despite making no headway in their research. But now, Spock was alone, and wholly grateful for it.

The pain was excruciating.

"Computer, lock door," his voice sounded heavy and gravelly even to his own ears.

He didn't know how much longer he would be able to hold out, the creature within him applying equal force against his control of the pain.

When he'd first awoken in Sickbay after being attacked on Deneva, Spock had succumbed to the creature's will. The voice inside his head screaming for him to steal the ship, to beam the entire compliment down to the surface so that the others could infect the rest of the crew and move on to the next solar system.

The second time he woke up, he was restrained to the biobed, half-sedated and with a migraine to end all migraines. "I am a Vulcan," he'd told himself. "There is no pain."

Truth be told there was pain, a lot of it. And it was only growing worse.

Spock pushed aside the specimen jar, folded his arms across the surface of the workbench and put his head down.

While he suffered from migraines regularly, thanks in no small part to competing brain chemistries, this one was different. It was worst, so much worse than anything he'd ever experienced before.

It had begun with the stabbing pain behind his eyes, making even those organs themselves painful. "Computer," he said again, "lights down seventy-five percent. Please." It was illogical to ask politely of the machine, it would obey any command he gave it regardless; his control was slipping and he was getting desperate.

With the lights down to a more manageable level, Spock now focused on the pain. The headache had moved from stabbing behind his eyes to pulsating through every part of his skull and down into his neck and shoulders, in fact, his whole body felt the insistent droning throb. It was pulsating through every part of him. He could *feel* the parasite growing inside him, its tentacles wrapping tighter and tighter around his spinal chord, the sharp tendrils stabbing into his brain. He was certain there was intracranial hemorrhaging.

His peripheral vision was all but gone, the rest was doubled, blurred with the full spectrum of flashing lights. Closing his eyes brought on dizziness that threatened to send him tumbling to the floor despite being seated already. Keeping his eyes open meant feeling like hot metal pokers were being pushed through to his optic nerves.

Every nerve in his body had been in overdrive for hours, they were curiously both numb and hyper-sensitive at the same time. His hands hurt, trembling, fingertips numb and tingling. Yet whenever he touched something, anything, regardless of what it was it felt like they were burning off. The same sensation had moved down into his legs. In fact every centimeter of his skin felt that same tingling-burning, he likened it to the feeling of having his skin frozen like ice and then shattering into a million pieces whence something broke that surface.

Spock was in more agony than he'd ever been in in his life.

"I am a Vulcan. There is no pain. I am a Vulca-fuuuuuuckkkkkk..."

The wave of nausea hit like a hurricane, he was barely able to make it to the lab's sink before retching for the umpteenth time.

He silently admonished himself for his illogical use of the human expletive, but that part of his mind told him that he had every right to given the circumstances. He took a shaky sip of lukewarm water, hoping it would stay down as nothing else had in the last six hours. He was in the beginning stage of dehydration on top of it.

It hurt to breathe.

His head felt heavy.

It felt as if his spine was being ripped vertically, vertebrae by vertebrae, through the skin between his shoulder blades.

Even through the tinnitus piercing in his ears, his ultra-sensitive hearing was able to detect the voices of Captain Kirk and Dr McCoy quietly coming down the hallway. He sank to the floor, folded his long frame in on itself and steadied his ragged breathing.

Spock quickly ordered the computer to return conditions inside the lab to daily working norms. He pulled the neural parasite inside the specimen jar back to its dock on the bench with quaking arms. He took a shuddering breath in as the doors slid open to Kirk and McCoy, "there is no pain."

"Observe Gentlemen."

...