I read (er, reread) it last night using the book-borrowing feature of archive.org which got them existentially sued: https://archive.org/details/bonepeople0000unse/. The mind-reading business hardly figures in the action; it's there, but marginal. The humans actually defeat the bone people by kicking one of them in the head (er, skull) and then blasting them with an air gun. Literally an air gun: it shoots air, and it turns out that air kills bone people. That was lucky!
I remain of the opinion that defeating mind-readers by keeping one's thoughts in the back of one's mind is the most interesting thing about the book, so it's not surprising that was what stuck in my mind, though not so much in the back. It's been in a trunk in the middle somewhere.
Later
No, that's not quite fair; you get halfway into this and it starts to be written like the Hadiths. "The Bone People do not think about a thing but what it is an evil thought." I'm always saying!
The total vocabulary of this book is 280 words, excluding proper names
and sound words. The 15 words in roman type should be familiar to
children reading on a third-grade level. The 20 words above third-grade
level are shown in italic type.
280 words seems rather few! That's probably why it reads like Gertrude Stein.