This is the Hundred-and-thirty-eighth in my one-book-at-a-time bookshelf.
I've added another Heinlein to my bookshelf. This one from 1957 but with a very new cover. I thought I'd read it but as I started I realised that this one, whose title I knew, had passed me by and I didn't know the story at all. What a treat. Not a long treat as I read it in the afternoon, and it had the unmistakable themes and characters of Heinlein, but a treat nonetheless.