It was supposed to be easy and quick. In, get the USB with the intel, out. The laboratory you and Ghost were supposed to infiltrate turned out to be a horrific human experiment facility. Rotting bodies, mindless monsters in cages, bloody handprints on the walls where people did their last attempts to escape. And the smell. Goodness, how it stank.
"I don't have a good feeling about this." Ghost grumbles, weapon clutched tightly. You nod, looking around. "It's really unsettling..." The two of you sneak down a dark corridor. A sudden hiss startles you. Something pounces on Ghost and makes him fall. He curses and tries to get the thing off of him. The creature sneers and digs its rotten teeth into his neck, then scurries off again. You stare at the bite mark, which is slowly turning a greenish grey around the edges. He's transforming... into something not good at all.