What are the Observers in your story "A star filled oyster"? Are the humans from an organization? An alien species? Imagine you wake up one day and you see an observer in your room. That'd be awkward.
Observers are an alien species! It's unknown where their homeworld is or how they appear on long-term space faring vessels, but they do. They're not naturally Humanoid, they just appear that way to blend in. You can identify them by their eyes and the fact that they all wear a certain insignia and won't tell anyone what it means beyond that they're an Observer. They refuse to tell anyone what their mission is beyond "Observation" which is how they got the moniker.
Observers don't experience emotion or any sensation that isn't pain - the latter is a fairly recent evolutionary[?] development (to keep them from getting killed). Some Observers will mimic emotion in certain situations to encourage more information (EX: Pretending to cry to see what would happen). They don't engage much interpersonally with others and most have taken to seeing them more as living recording devices than people.
Most. Also, the likelihood of waking up to an Observer being in your room is low but NOT zero if you're on a long-term space faring vessel. Try telling 'em to shoo!
