O Brave New World...

Probably the way to get hints of it would be her early correspondence, particularly with her family. But who even knows if that's still extant? It's the sort of thing the Stalinists meticulously, cultishly collected and preserved for Lenin (if only to redact it), but Luxemburg never got that kind of treatment, for better and worse.

As for Lewis, I was made to read The Lion, the Witch and the Wardrobe in 4th grade, and since I was hip to the Christian subtext, and vehemently, almost bigotedly Jewish at the time, I didn't enjoy it in the least. So I never felt the urge to examine any of his other writings.