Between Planets is a science fiction novel by Robert A. Heinlein, originally serialized in Blue Book magazine in 1951 as "Planets in Combat". It was published in hardcover that year by Scribner's as part of the Heinlein juveniles.
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 ...
- Chaste Hero: Isobel convinces her father to loan Don money, despite the fact he has nothing to guarantee it. When he asks her to hold on to a ring for him, she is startled about being given a ring and he doesn't understand why a woman would consider being given a ring something unusual. When her father finds out that Don gave his Isobel a ring, he questions it also, but Don is still clueless about why it might be considered strange.
- The Coroner Doth Protest Too Much: The above-mentioned "heart failure."
- Dead-Man Switch: One is built into the Venusian superscience ship "Little David" to prevent it from being captured by the Federation.
- New Neo City: Some early chapters are set in "New Chicago."
- Science Marches On: Jungle Venus and Dying Mars.
- Victoria's Secret Compartment: Isobel hides Don's ring ... somewhere. It's a novel for pre-teens and young-teens.
- The War of Earthly Aggression: Pretty much the driving force behind the entire plot.
- Work Off the Debt
- Zeerust: To show how technologically advanced the setting is, the story starts with Don taking a call on his mobile telephone - mounted in his horse's saddle.