Well this was a disjointed little read. Not thoroughly unenjoyable, but kind of perfunctory in its plot. And indeed, there are 7 eyed dragons from Venus. Why 7? I don’t know.
There are a lot of Heinlein’s usual themes: politics, a dislike of big government, soldiers. The mystery of the “secret message” was kind of weak.
Not his best. 2 Helmets out of 5.