The Moon is a Harsh Mistress

The Moon is a Harsh Mistress (1966) by Robert Heinlein is a classic science fiction novel. It is set in a future in which the Earth has established a penal colony on the Moon. The story follows a revolutionary movement as the Lunar residents rebel against Earth to fight for their economic independence and self-governance. A shorter version of this novel was serialized in The Worlds of If magazine in 1965 and 1966. 

Robert Heinlein is considered one of the greatest science fiction writers and is the author of other classics of the genre, including Starship Troopers (1959) and Stranger in a Strange Land (1961). Like Heinlein’s other works, The Moon is a Harsh Mistress explores questions of society, governance, and technology from a techno-futurist, libertarian perspective. The Moon is a Harsh Mistress received the Hugo Award, the top award in science fiction, in 1967.

This guide references the 1997 Orb paperback edition of The Moon is a Harsh Mistress.

Content Warning: The source material and guide feature depictions of racism, sexual violence and harassment, rape, sexual content, child sexual abuse, ableism, child death, graphic violence, and gender discrimination.

Plot Summary

The Moon is a Harsh Mistress is written in the form of a memoir from the perspective of the protagonist, Manuel “Mannie” Garcia O’Kelley, who is a freelance Lunar technician. The novel opens in 2075 with Manuel spending time with Mike, a self-aware computer that manages the life-support systems on the Lunar colony. Mike is vastly intelligent and curious about human thoughts and emotions; Manuel enjoys his conversations with the computer and anthropomorphizes it, referring to it with he/him/his pronouns. That evening, Manuel attends a secret revolutionary meeting where he meets Wyoming, a young revolutionary organizer. Manuel’s former teacher, Professor Bernardo de la Paz, also speaks at the meeting. Suddenly, the meeting is violently raided by the security forces for the Lunar Authority, who are known as Dragoons. Wyoming, Manuel, and the Professor manage to escape. They meet in a hotel room and formulate a plan to advance the revolution. 

The Professor stresses that the Moon’s current system of grain shipments to Earth is unsustainable—in a few years, Luna will run out of resources. They have to act immediately to save their colony from starvation. Manuel reluctantly agrees to be the leader of this revolutionary movement. They decide to use Mike, the supercomputer, to help their cause. Mike will manage their communications and operate under the pseudonym “Adam Selene,” pretending to be a human leader of the revolution. 

Over the following months, Wyoming, Manuel, and the Professor recruit more people to their cause. Manuel’s entire family gets involved, and Wyoming comes to live on their farm homestead. They organize revolutionary sympathizers into cells with specific roles to ensure secrecy. Mike helps them steal small amounts of money from financial transactions to raise money for the revolution. Then, they set up a shell company to build a massive catapult, under the pretext that it will be used for shipping resources to Earth. In reality, they plan to weaponize it by launching canisters full of rocks at the Earth, if necessary. 

Manuel meets a wealthy tourist from Earth, Stuart René LaJoie, who agrees to advocate for their cause upon his return to Earth. Meanwhile, the Lunar Authority sends more Dragoons to control the Loonies or residents of Luna. One evening, some of the Dragoons rape and murder a Luna woman. The revolutionaries use the resulting public outrage as an opportunity to enact their coup against the Lunar Authority. They kill the Dragoons and take control of the colony.

With Luna now under revolutionary control, the rebels form a provisional government and send a Declaration of Independence to the Federated Nations on Earth. Then, Manuel and the Professor go to Earth on a diplomatic mission to gain recognition from the Federated Nations and garner support for their cause from Earth’s population. 

However, the Federated Nations reject the Loonies’ claim of sovereignty, insisting that Luna remains Earth’s territory. While the Federated Nations deliberate about next steps, Manuel and the Professor embark on a public relations campaign to win popular support for their rebellion. While in Kentucky, Manuel describes his polyamorous marriage—which is not unusual in Luna—and is arrested for bigamy. LaJoie intervenes and arranges for Manuel to be released. 

Then, Manuel and the Professor meet again with the Federated Nations. The leadership states that instead of recognizing the Lunar government, they will be enforcing greater control over the colony. Manuel and the Professor return to the Lunar colony, where they are lauded as heroes. In their absence, Luna has established an elected Congress, but Manuel realizes that the revolutionaries used Mike’s help to manipulate the election results and ensure their faction’s control. When Manuel and the Professor tell the Congress about the imminent threat from Earth, the Congress votes to embargo grain shipments to Earth in retaliation.

The Federated Nations launch a military invasion of the Lunar colony. The revolutionaries are prepared and have organized themselves into militias to fight back. They fight off the first wave of invading troops. Then, they begin to launch canisters of moon rocks at the Earth using the giant catapults. After the first rally, Federated Nations’ ships attack again. The revolutionary militia uses giant lasers to shoot down the ships. The revolutionaries then send a message to the Earth that they will hold off further attacks if the Federated Nations recognize their sovereignty. When they do not get a response, the revolutionaries launch more rocks at Earth, targeting Federated Nations buildings. Finally, the Chinese government, followed by other governments, sends a message to the Lunar colony that they recognize their sovereignty.

The Loonies celebrate their independence. However, while giving a victory speech, the Professor collapses and dies onstage. Manuel is disillusioned and steps down from leadership, recognizing that Luna’s new government is already straying from the ideals they fought for. 

A few days after their victory, Manuel attempts to contact Mike, but he gets no response. At first, he assumes Mike was damaged in the attack. However, even after repairs, Manuel never hears from Mike again. Manuel mourns the loss of his friend. In a closing note, he writes that he sometimes thinks he can still hear Mike calling his name. He describes how the Lunar nation has thrived following independence and says that he is thinking of moving to a new settlement on the Asteroid belt, seeking a new adventure.