Between Planets
Robert A. Heinlein
 A young man named Don Harvey leaves his dude ranch high school on Earth to go to his scientist parents on Mars. He visits an old family friend who asks him to deliver a ring to his father, but they are both later arrested by security forces. Harvey is released and given his ring back, after it has been examined; he is told that his friend has died of "heart failure." It is only later that he realizes that all deaths can be described that way. Harvey boards a shuttle to a space station orbiting the Earth. The station doubles as a transshipment terminus and a military base, armed with missiles to keep restive nations in check. On the trip up, he befriends one of his fellow passengers, a Venusian "dragon" named Sir Isaac Newton. Sir Isaac is a renowned physicist who can speak English using a portable device. Harvey gets caught up in the Venusian war of independence when the station is captured by the colonials in a surprise raid. Most of the other travelers are sent back to Earth, while a few decide to join the rebels. Harvey is in a quandary. The spaceship to Mars has been confiscated, but he remains determined to get there, by way of Venus if necessary. Because he was born in space, with one parent from Venus and the other from Earth, he claims Venusian citizenship; more importantly, Sir Isaac vouches for him. He is allowed to tag along, which turns out to be very fortunate for Harvey. The rebels blow up the station to stir up trouble for the Earth government. When the shuttle returns to Earth with its radios disabled, the military assumes it has been booby-trapped and destroys it, killing all aboard. On his arrival on Venus, Harvey finds that his Earth-backed money is now worthless. A banker lends him money, telling him to pay it forward. He gets a job washing dishes for his keep for Charlie, a Chinese immigrant who runs a small restaurant. He befriends a young woman, Isobel, when he tries to send a message to his parents. However, communication with Mars has been cut due to the hostilities. Harvey settles in to wait out the war, when the war comes to him. Earth sends a military force to put down the rebellion. The Venusian ships are destroyed in orbit and the ground forces are routed. Charlie is killed resisting the occupying soldiers. Harvey is rounded up and questioned by a senior security officer, who is very eager to get his hands on Harvey's ring. Luckily, Harvey had given it to Isobel for safekeeping and he does not know where she is or whether she is even alive. Before he can be interrogated with drugs, he escapes and joins the Venusian guerrilla forces. Harvey becomes an effective commando. In time, he is tracked down by the leaders of the resistance, who turn out to also be looking for the ring. Isobel and her father (who is an important member of the rebels) are safe at the very base where Harvey is taken. The seemingly valueless ring turns out to be carrying the secret of scientific breakthroughs resulting from archeological studies of an extict alien civilization on Mars. With Sir Isaac's assistance, it is used to secretly build an advanced spaceship that is much faster than any other vessel in existence, with revolutionary weapons and defenses also derived from the new technology. As the only combat veteran with knowledge of the ship, christened Little David, Harvey is recruited for its maiden voyage, manning a self-destruct mechanism, with strict orders to blow up the ship if it is in danger of being captured. Little David intercepts and defeats a group of warships on their way to Mars to crush the revolt there. Afterwards, Harvey is probably reunited with his parents, although the story ends before then.