All Cats Are Gray by Andre Norton - An odd story, made up of oddly assorted elements that include a man, a woman, a gray cat, a treasure-and an invisible being that had to be seen to be believed.
Steena of the spaceways-that sounds just like a corny title for one of the Stellar-Vedo spreads. I ought to know, I've tried my hand at writing enough of them. Only this Steena was no glamour babe. She was as colorless as a Lunar plant-even the hair netted down to her skull had a sort of grayish cast and I never saw her but once draped in anything but a shapeless and baggy gray space-all.
Steena was strictly background stuff and that is where she mostly spent her free hours-in the smelly smoky background corners of any stellar-port dive frequented by free spacers. If you really looked for her you could spot her-just sitting there listening to the talk-listening and remembering. She didn't open her own mouth often. But when she did spacers had learned to listen. And the lucky few who heard her rare spoken words-these will never forget Steena.
She drifted from port to port. Being an expert operator on the big calculators she found jobs wherever she cared to stay for a time. And she came to be something like the master-minded machines she tended-smooth, gray, without much personality of her own.
But it was Steena who told Bub Nelson about the Jovan moon-rites-and her warning saved Bub's life six months later. It was Steena who identified the piece of stone Keene Clark was passing around a table one night, rightly calling it unworked Slitite. That started a rush which made ten fortunes overnight for men who were down to their last jets. And, last of all, she cracked the case of the Empress of Mars.
