Parsley

There's a new crew member on your ship, and she's commandeered one of the spare rooms for—

"A lab!" She says, shaking a test tube at you in a clear attempt to be authoritative. It's not working really well and both of you know it. "I need a space to work! You don't want me storing my experiments in the hallways or the mess hall, do you? Lots of dangerous and volatile materials in here! They'll kill you if you touch them! They'll dissolve your skin!" Which would be terrifying, if she could do a good job of making it sound believable. But she keeps freaking out at you, so you decide to leave her alone.

You're not the only member of your crew that's weirded out by this new Xero. The quartermaster isn't allowed a moment of peace until he agrees to provide her with a venom sample from his fangs. She practically bribes one of the cooks in exchange for a chance to study their insectoid eyes. After a while, she even asks you if she can take a sample of your fur—your species is known for its thick winter coat.

"I'm interested in the adaptations that different species have evolved," she admits as she works. "So many different traits exhibited by so many different organisms! I don't really have anything myself. What is it like to have wings or bioluminescence or venom? What is it like to feel so powerful?"

"Uh," you say, feeling that any response you could give seems lame in the face of such odd, fervent enthusiasm. Xeros...they're known for their extraordinary adaptive abilities, even among all the unique and unusual alien species in the system. And they modify themselves sometimes, even. "Are you going to enhance yourself with some of the samples you took?"

Parsley just says: "No."

(And you, personally, will forget you ever had this interaction, and after your contract ends and you depart for your own little life somewhere on a distant star, will never have the chance to look back on your conversation with her and realize the dramatic irony.)