Among every world ever settled by humanity, none carries a darker reputation than Erebus. Official records designate it as Quarantine World Zero, placing the entire planet under permanent military exclusion. No civilian traffic is permitted within the system. Unauthorized vessels are intercepted long before reaching orbit, and every Colonial Marine is taught the same lesson during training:
If your orders send you to Erebus, something has already gone terribly wrong.
Erebus was never intended to become a colony. It began as a classified research initiative jointly funded by Colonial Administration, the Colonial Marine Corps, and several of humanity's largest corporations. Its remote location made it the ideal site for dangerous projects too controversial to perform anywhere near populated space. Over several decades, dozens of underground laboratories, military installations, synthetic testing facilities, weapons proving grounds, and biological containment complexes were constructed beneath its barren surface. Above ground, only a handful of administrative buildings and landing facilities hinted at the immense infrastructure hidden below.
Officially, Erebus conducted research into hazardous pathogens, advanced synthetic intelligence, planetary survival systems, and next-generation military technology. In reality, the world became humanity's most secretive scientific playground. Recovered alien organisms, unknown biological samples, recovered artifacts, experimental weapons, and classified synthetic prototypes all found their way to Erebus under layers of military secrecy.
Then communication stopped.
The first reports described isolated containment failures. Hours later, emergency evacuation orders were transmitted across every installation. Within days, orbital surveillance recorded explosions, power failures, and widespread structural collapse across multiple research sectors. Automated distress beacons activated one after another before falling silent. Rescue fleets dispatched to investigate encountered destroyed facilities, abandoned landing zones, and scattered survivors whose accounts often contradicted one another. Before a complete evacuation could be organized, Colonial Command declared the entire planet lost.
The quarantine has never been lifted.
Today, orbital defense satellites, automated weapons platforms, and Marine patrol groups enforce an exclusion zone around the planet. Officially, the purpose is to prevent biological contamination from leaving the surface. Unofficially, few people truly know what remains alive below.
Reconnaissance missions continue under the highest levels of classification. Some teams search for valuable research that could never be replicated. Others recover encrypted data cores, prototype technology, or abandoned synthetic systems. Most return with only fragments of information. Some never return at all.
The surface appears lifeless from orbit, scarred by abandoned facilities, collapsed launch complexes, and the remnants of military bombardment intended to sterilize critical installations. Beneath that desolation lies an immense underground network of laboratories, transit tunnels, reactor complexes, containment vaults, and research cities stretching for hundreds of kilometers. Entire sectors remain sealed exactly as they were on the day quarantine was declared.
Rumors surrounding Erebus have grown into legend among Colonial Marines. Veterans speak of automated security systems that still identify themselves as active personnel centuries after losing command authority. Others tell of research wings operating on emergency power, their synthetic caretakers continuing experiments despite having no human staff remaining. Long-range sensors occasionally detect power fluctuations, encrypted transmissions, and unexplained movement deep beneath the surface. Every official investigation ends with the same conclusion:
Source undetermined.
For corporations, Erebus represents unimaginable scientific value. For governments, it is a reminder of how easily secrecy can become catastrophe. For the Colonial Marines, it is the assignment no one volunteers for.
Every expedition begins with the same objective: recover what can be saved.
Every expedition ends with the same question:
What is still alive beneath Erebus?