They should've known better than to ask for blood tests.

Nathan had wondered if it would kill them slowly, infecting them and waiting until the right time to strike. But it had been impatient. As soon as the syringe left his body, the blood in it was no longer controlled by his own will. It shattered its useless container, reaching out with long red tendrils and traveling down their throats, joining with the bloodstream until it finally reached their hearts. The doctors collapsed to the floor, their hearts stopped. Nathan almost pitied them. They hadn't lived long enough to see that their deaths were a consequence of their own actions.

But he didn't have time for pity. No one would pity him when they found him surrounded by bodies, the blood in their veins still thrumming through their corpses even after death. He ran from the hospital, careful not to be seen. It wasn't fond of being looked at.

When Nathan reached his home, he locked the doors, barred the windows, and ran to the mirror. He stared in horror at his eyes, which were bright red, covered in blood.

It had already happened.

He was too late.

"No, no no no," he whispered. He tore off his glasses and clawed at his eyes. If he could just get them out, maybe he would be safe. Maybe it would be gone.

His hands stopped in their tracks. Nathan knew instantly that he was no longer in control.

It was angry.

His limbs jerked around like puppets on a string, the blood in his veins pulled the rest of his body along. His heart started and stopped. It wanted him dead.

But maybe death was better than having it reach his brain. Having Nathan become a prisoner in his own body, just a vessel for a parasite that grew stronger every day.

It wanted to leave. It was going to get rid of him. He was no longer a good host.

"No, please!" Nathan whimpered. It ignored him.

"PLEASE!" he screamed again. "I don't want to die."

But it didn't care. It would live on without him. He was a necessary casualty.

"Why me?" he asked. Why had he been chosen, forced to spend the last three weeks with a parasite attatched to his blood? Why was he forced to choose between death and spreading it to another?

It was getting impatient. It was time for it to leave.

Every drop of blood in his body moved at once. Nathan screamed, once, twice, three times as his blood vessels ripped apart, a flood of the dark red liquid bursting out. He was shredded to pieces. His own blood was pulled out of his skin, leaving trenches in his flesh where the vessels used to be.

Nathan's corpse fell to the ground. It reached out the tendrils of blood and flew out of the room. It would need to find a new host. A better one.

It went out to hunt.