[Ransom answered,] “Yes. I shall arrive knowing the language. It saves a lot of trouble—though, as a philologist I find it rather disappointing.”
“But you’ve no idea what you are to do, or what conditions you will find?” [asked Lewis.]
“No idea at all what I’m to do. There are jobs, you know, where it is essential that one should not know too much beforehand ... things one might have to say which one couldn't say effectively if one had prepared them. As to conditions, well, I don’t know much. It will be warm… Our astronomers don’t know anything about the surface of Perelandra at all. The outer layer of her atmosphere is too thick" [answered Ransom].
C.S. Lewis, Perelandra (1943) Chapter 2.