Okay, this is one of several of my favorites from Heinlein. We open with teenager Don Harvey out in the southwest desert on his horse. His horse is startled and Don draws his pistol and shoots the nasty rattlesnake. Old West suddenly meets the future as Don gets a cell phone call that he is being picked up by helicopter for an emergency. It turns out that Earth is at odds with the colonized planets (particularly Venus and Mars). Because of the potential of war, he is being recalled to Mars.
There is plenty of adventure before Don even gets off Earth, but things take a nasty turn when he gets to the relay station which has been taken over by Venerian troops. The Venus rebels destroy the station, and Don finds himself declaring Venus citizenship and is whisked off to Venus, instead of his home on Mars.
What happens to him as he adapts to a planet he has not been on since early childhood draws out the best and worst of humankind, which is further elaborated upon in a later favorite novel, Citizen of the Galaxy… more on that on another post.
This is first and foremost another of Heinlein’s juvenile adventure stories in the arena of science fiction, but Heinlein is starting to address more complex issues. Characters are no longer all good guys or bad guys. But the dissonance is not carried beyond the bounds of a good story for teenagers. Worth the read even today,