This one seems to annoy heinlein fans who feel it encroaches on his more sci-fi works. I can see where they're coming from, but honestly, it's just a great romping read. Lying on the grass on a sunny afternoon with a cold drink and an hour or so to kill, in my case. Plot? what plot? it's your standard hero-on-an-adventure thing, with the beautiful woman thrown in for fun. somehow it's all tied together though, and made me want to carry on with it despite the sheer sillyness.