Revision 1

Overview

Project Caliban is a secret weapons program that players encounter in The Expanse: Osiris Reborn. The project aimed to create protomolecule-human hybrid supersoldiers by deliberately infecting human subjects with the protomolecule. The resulting hybrids are among the most dangerous enemies in the game. The corporate subsidiary Protogen that studies the protomolecule is confirmed to appear in the game, and sources have indicated that its most sinister project, the human-protomolecule hybrid Caliban, will also show up.

Background

In The Expanse lore, Project Caliban was operated by Protogen and its parent corporation Mao-Kwikowski Mercantile, with cooperation from elements within the United Nations and Martian Congressional Republic governments. The project's goal was straightforward: use the protomolecule to create controllable supersoldiers that would give their sponsors an overwhelming military advantage.

The project's name comes from the character Caliban in Shakespeare's The Tempest, a monstrous figure born of a witch and a devil. The second book in The Expanse series, "Caliban's War" by James S.A. Corey, takes its title directly from this project and the conflict it sparks. The game takes place during the timeframe of the first two books (Leviathan Wakes and Caliban's War), placing Project Caliban squarely within the narrative window.

The Hybrid Creation Process

To create hybrids, Protogen and Mao-Kwikowski kidnapped children and transported them to Prospero Station, an officially decommissioned facility on Io, one of Jupiter's moons. The children were infected with the protomolecule under controlled conditions, and researchers attempted to guide the transformation process to produce beings that could function as soldiers.

The resulting creatures were a horrifying fusion of human and alien biology. Although roughly humanoid in shape, the hybrids are visibly inhuman. Their heads are approximately twice the size of a normal human head and covered in protruding growths. Their skin is coated in black, chitinous scales. Their hands are oversized and elongated. Their eyes glow with a bright blue light. The hybrids are immensely strong, fast, and durable, making them lethal in close combat.

Combat Capabilities

The first field test of a hybrid was conducted on Ganymede, one of Jupiter's agricultural moons. A single hybrid was secretly deployed against a United Nations Marine patrol. The hybrid killed the UN soldiers, then engaged a Martian Marine Corps squad that had been stationed nearby. It killed every Marine except one: Gunnery Sergeant Bobbie Draper, the sole survivor, who went on to play a major role in exposing the conspiracy.

The Ganymede incident demonstrated both the hybrid's terrifying combat effectiveness and the project's central problem: the protomolecule could not be fully controlled. The researchers on Io were unable to implement reliable behavioral constraints. The hybrids were weapons, but they were weapons that could not be reliably aimed.

Project Caliban in the Game

The game spans the timeframe of the first two Expanse books, which means Project Caliban is active during the events the player experiences. Sources have confirmed that the player will encounter "one of the dreaded Project Caliban subjects" during the campaign. Given the hybrids' established combat capabilities, these encounters likely represent some of the game's most dangerous and memorable combat challenges.

The connection between Project Caliban and the broader conspiracy the player uncovers is direct. Protogen is the game's primary antagonist, and Project Caliban is the logical endpoint of Protogen's protomolecule research: turning the alien substance into a weapon that can be deployed on a battlefield. For the player, encountering a hybrid represents a threat that cannot be handled with standard weapons and tactics. It forces adaptation, creative use of gadgets and companion abilities, and careful tactical thinking.

Prospero Station and Io

The facility where the hybrids were created is Prospero Station on Io, which had been officially shut down before being secretly repurposed by Mao-Kwikowski for the project. Io is one of the game's confirmed visitable worlds alongside Ganymede, Mars, Luna, and Ceres. Whether the player directly visits Prospero Station or encounters its output elsewhere in the solar system has not been confirmed in detail, but the project's ties to Io and the game's inclusion of Io as a location suggest a significant story connection.

Discovery and Exposure

In the established lore, Project Caliban was eventually exposed. Bobbie Draper's survival on Ganymede and her subsequent investigation, combined with the political work of UN diplomat Chrisjen Avasarala, led to the project's discovery. The Io Campaign, a military assault on Prospero Station, shut the project down and ended Mao-Kwikowski's involvement. This exposure occurs during the events of Caliban's War, which falls within the game's timeline.

The game's narrative runs parallel to these events. The player is experiencing the repercussions of the same conspiracy from a different angle. While the books follow Holden, Bobbie, and Avasarala as they uncover the truth about Project Caliban from their respective positions, the player encounters it as a Pinkwater Security mercenary caught up in events far beyond their original pay grade.

Key Facts