You get out of the vents, and keep walking, until you see a strange eel crawl out of the vents. It doesn't do anything, it just sits there. then, its head explodes. A strange humanoid creature with a sideways mouth where its stomach should be pops out. No arms, no organs, just legs, head, and hunger. Stay at a medium distance, or Specimen 10 will eject its parasite from its body, which is faster, and deadlier than its humanoid counterpart.