"Sera's dying, Marcus—the whole planet's infected. It's the Imulsion that's killing it. It was always the Imulsion, you see, and I can stop it."
Adam Jonathon Fenix[1]

Imulsion was a luminescent, highly volatile, low-viscosity fungal fluid originally discovered by an oil exploration drill on the planet Sera. The discovery of the substance and its use as a fuel played a key role in Seran and Locust history. Control of Imulsion was the main cause of the Pendulum Wars, which weakened humanity's unity but gave them the strength to fight the Locust Horde on Emergence Day.[2]

During the Lambent Pandemic, Professor Adam Fenix determined that Imulsion was actually a parasitic life-form feeding off other beings, including humans. The health effects caused by Imulsion led to the creation of the Locust Horde through genetic experimentation, and Adam's failure to provide Queen Myrrah with a solution to stop Lambency and the Lambent War resulted in the Locust War. In 17 A.E., Imulsion and its resulting Lambent lifeforms were destroyed by Adam with the Imulsion Countermeasure Weapon.[3]



The origin of Imulsion remains a mystery. It is unknown if it has existed on Sera since the first origins of life or it somehow developed or was introduced during human history. However, it's possible it was developed during prehistoric Sera when Riftworms were active in creating the Hollow and their excrement allowed for the creation of life in Hollow - possibly creating Imulsion from the Riftworms.

Imulsion was a living, fungal, parasitic organism - acting as a mycelium in the Hollow. Despite no apparent signs of life such as response to stimuli, methods of reproduction, or metabolic process - it had a life cycle and was very much mutagenic and highly invasive. The vapors and fumes given off by Imulsion were actually infectious spores that could infect potential organisms.

Discovery and Lightmass ProcessEdit

"Well, in a few words: Imulsion is a newly-discovered fuel source that may render Sera's energy crisis non-existent. Cheap and limitless, Imulsion may be the answer to all of Sera's fuel problems."
—An unknown scientist explaining Imulsion's potential as a fuel source.

It is unknown when Imulsion was discovered by humans - but at the time was considered to be more of a scientific curiosity than a practical resource after its discovery, and was essentially useless until Dr. Helen Cooper created the Lightmass Process. The process was capable of refining Imulsion into an efficient energy source.[4] For a planet desperate for energy and facing something of an energy crisis in the long term, Imulsion was the perfect solution: efficient, clean and fairly abundant.

The founding of the Lightmass Process thrust Sera from the Age of Silence into the Gold Rush, effectively saving humanity from a global crisis. However, Imulsion reserves were only exclusive in certain areas on Sera - within particular nations. The nations with rich Imulsion reserves were combined under a singular government: the Coalition of Ordered Governments. As the Gold Rush continued, the Coalition or COG began to reap the profits and become a globally economic and political superpower while the others were denied profits.

Pendulum WarsEdit

Pendulum war

Soon after Imulsion turned into fuel, the COG and UIR fought over it.

Over time, Imulsion speculation on the financial markets ran rampant and entire currencies and economies became linked to its value. This eventually resulted in a large economic collapse on the planet Sera when extremely low Imulsion prices crippled the financial sector.

The economic crisis sparked military actions, and the countries under the Coalition of Ordered Governments that possessed an abundance of Imulsion reserves soon found themselves at war with those nations who were not as fortunate, now under the political regime of the Union of Independent Republics, in a conflict known as the Pendulum Wars.[5] The Pendulum Wars became a global conflict that would last for seventy-nine years, with millions dead.

Health CrisisEdit

Meanwhile, the miners of Imulsion and their families in the Coalition's head nation, Tyrus, began to become poisoned by Imulsion. It was discovered that exposure to Imulsion vapors during Imulsion mining and refining led to a fatal respiratory condition known as Rustlung. The Coalition of Ordered Governments feared the potential economic and political ramifications if it were known that Imulsion caused health problems. In order to resolve the health crisis, the Department of Health under the Monroe Administration opened the New Hope Research Facility to house the children of Imulsion-poisoned miners, study the toxicity of Imulsion, and discover a cure for Rustlung.

Famed geneticist, Dr. Niles Samson, was established Director of New Hope and their research to cure Rustlung. Initially injecting the children with concentrated doses of Imulsion, Samson discovered that exposure to Imulsion caused immediate cell stress and could metastasize to other parts of the body and cause death. He also noted that other cells exposed to Imulsion caused point-mutations. Fellow scientist, Dr. Torres, then discovered a female child named Myrrah who exhibited a genetic immunity to Imulsion and Rustlung. Upon further research, it was revealed that Imulsion exposure actually benefited Myrrah by improving her immune system and decelerated her aging by 50%. Dr. Samson hoped to replicate her results in other children but was unsuccessful.

Dr. Samson then looked to indigenous creatures of the Hollow. Due to their proximity to Imulsion, he believed they also held a genetic immunity to Imulsion. Manipulating the point-mutations, Dr. Samson began to mutate the children with the DNA of the Hollow creatures. This resulted in the children transforming into aggressive and genetically unstable creatures Niles called Sires. Due to the unethical experimentation and attacks on the staff by the Sires, many employees of New Hope resigned and leaked information to the public and government. Chairman Monroe discovered the wrongdoings of New Hope and ordered the facility shut-down and all involved to be indicted. However, Dr. Niles Samson - along with his remaining loyal employees, many of his subjects and research, and Myrrah disappeared without a trace.

Unknown to Monroe, a fringe political group of pragmatists resided within his own administration. They contacted Niles Samson and revealed that they believed in his work and wished for him to continue to not only cure Rustlung, but to use his genetic research to end the Pendulum Wars by creating advanced soldiers. He agreed and the group relocated his people, subjects, and research to secret facility at Mount Kadar. There, he began making hybrids by combining the embryonic stem-cells of Myrrah with Sire DNA, resulting in the creation of the Locust Horde. However, the Locust longed for independence as they felt imprisoned, oppressed, and tortured. Myrrah later gave birth to a human daughter named Reyna, but was led to believe by the scientists that Reyna was killed when the father, Dr. Torres, tried to escape with her from the facility.

Locust Horde and Lambent WarEdit

Due to Myrrah's grief and connection with the Locust, she became their Queen and led the Locust to slaughter all the scientists and escape the facility. She then led her people underground into the caverns of Mount Kadar where they built their own civilization: Nexus. As the Pendulum Wars raged on the surface, the Locust grew and became organized and developed their own culture, religion, science, and technology. Queen Myrrah and scientist Ukkon then used Niles Samson's Imulsion research to genetically enhance the Locust and the creatures of the Hollow into biological weapons and transportation.

By 17 A.E., many of the creatures in the Hollow began mutating and becoming infected with Imulsion to the point of becoming a host, known as the Lambent. Eventually, members of the Locust Horde began to become Lambent as well. The Lambent were capable of mutating and evolving on command and would self-destruct upon death in an attempt to spread Imulsion fumes and reproduce. By 7 A.E., the Locust Horde began experiencing an epidemic, resulting in a conflict known as the Lambent War. As the Locust continued to lose ground and people to the Lambent, Queen Myrrah considered a plan of emerging from the underground and colonizing the surface to escape the Lambent, and would eradicate the entire human race in order to occupy Sera.

In 5 A.E., Professor Adam Fenix was contacted by Queen Myrrah. She revealed her potential plans to destroy the human race in order to escape the Lambent, but was willing to stay underground if he could resolve the Lambency without harming the Locust. Adam Fenix agreed, but discovered that all biological countermeasures would not work against the ever-evolving Imulsion. He also discovered that any physical countermeasures, such as radiation, would harm the Locust because their genetics contained Imulsion from their ancestors. Due to his inability to cure the Lambency, and the Coalition demanding he complete the Hammer of Dawn to end the Pendulum Wars - Queen Myrrah decided to go with her original plan to escape the Lambent by colonizing the surface.

Locust WarEdit

After 79 years of fighting, the Coalition won the Pendulum Wars against the Union of Independent Republics. Six weeks after their victory, however, the Locust emerged and began a genocidal campaign until humans went extinct. Within the initial attack, 25% of Sera's population was killed. The humans were pushed back to cities located on the Jacinto Plateau, namely Ephyra and Jacinto City. Meanwhile, the humans continue to mine Imulsion using derricks, as the Hollow was occupied by the Locust, who also used Imulsion as a source. By 14 A.E., the COG developed a Lightmass Bomb and a Sonic Resonator. By using the resonator, they would map the Locust tunnels, and then send the Lightmass Bomb to destroy them. The Lightmass Bomb was successfully deployed during the Lightmass Offensive. However, the heat from the bomb caused the Imulsion in the Outer Hollows to evaporate, exposing the remainder of humanity to Imulsion fumes and causing a new wave of Rustlung.

Six months after the Lightmass Bombing, the Locust were preparing to sink Jacinto as they did with Tollen, Montevado, and Ilima, using the gigantic Rift Worm that had been awakened by the Lightmass Bomb. The COG then deployed Operation: Hollow Storm, sending a majority of their forces underground to defeat the Locust once and for all. The Rift Worm was destroyed, and the COG then discovered the Civil War between the Locust and Lambent as the reason for the Locust invading the surface. The COG then discovered a recording from Adam Fenix detailing that sinking Jacinto would flood the entire Hollow with seawater, drowning anything underground. Jacinto was then sunk by the COG when a Brumak became infected with Lambency and was detonated by the Hammer of Dawn. The city fell and the walls of the plateau collapsed with seawater, drowning a majority of the Locust. The COG then eventually relocated to the island of Vectes.

Lambent PandemicEdit

Despite a conflict with the Stranded on the island of Vectes, the COG had momentarily found some peace. But by 15 A.E., the Imulsion quickly polluted Sera's oceans and landscapes, giving rise to new and more aggressive Lambent lifeforms, among them the Lambent Stalks, Lambent Leviathans, and Polyps. The Lambent began to sink ships and invade inland, killing and infecting everything in their path. Meanwhile, Adam Fenix, who had been kidnapped in 10 A.E. by Chairman Richard Prescott, was situated in Azura, a secret COG facility, taking samples from the Vectes attacks and developing a solution for the Lambent Pandemic, a targeted radiation pulse-wave that would only kill cells infected with Imulsion, otherwise known as the Imulsion Countermeasure Weapon. Prescott then abandoned the COG to bring more samples for Adam and help develop the weapon, as Sera had a few years left before the entire planet became infected. Adam then began injecting himself with Imulsion in order to study its lifespan and reproduction, to ensure the countermeasure would work.

By 17 A.E., the weapon was completed, but Azura was invaded and captured by the Locust, with Adam left alive and Prescott escaped to find reinforcements. The COG had since been disbanded, but reorganized to take back Azura and activate the countermeasure. By that time, humans began becoming Lambent along with all other species on the planet, as the Imulsion reaches a critical stage in its life cycle. Adam detonated the countermeasure, which resulted in the death of Adam Fenix, Imulsion, and any life-form heavily colonized by Imulsion while those less infected were cured of their affliction.


Though Imulsion and the Lambent were destroyed by the weapon, the Locust were not killed but instead triggered a mutation where all Locust life-forms were cocooned in an Imulsion crystalline shell, where they evolved until 42 A.E. into the Swarm. Over the next twenty-five years a technological dark age would define the civilization that was attempting to rebuild itself. Humans were forced to return to and consult traditional and alternative energy sources in the hopes of restoring the Seran society that had existed during the Era of Silence. Due to the ingenuity of Damon Baird, the newly reformed COG turned to automation and fabricators to rebuild civilization.

Known Areas with ImulsionEdit

Known Imulsion Fields/Facilities/PlatformsEdit

Mining MethodsEdit

Old oil rigs and Derricks were repurposed to extract Imulsion from pockets near the surface. Facilities like Lethia Imulsion Factory and the Denava Imulsion extraction facilities mined deep into the Outer Hollow, and Imulsion crystals were used for military purposes.[9] Offshore Imulsion deposits required advanced drilling platforms in order to be tapped.


"At the time of its discovery, there was no reason to believe that Imulsion was a living organism. It exhibited no observable characteristics of typical life: no response to stimuli, no apparent method of reproduction, and no metabolic process. It has since become clear that this is not the case. Though our examinations were sound, the assumptions upon which they were based - our narrow definitions of life - were not. It is very definitely alive, mutagenic, and highly invasive. Viewed in that light, Imulsion exhibits characteristics that resemble the structure and life cycle of many fungi. The bulk of the organism - in liquid form - is underground like a mycelium. The evidence of its existence on the surface in the form of stalks is the equivalent of fruiting bodies. Its periodic vapor-like emissions are perhaps best likened to spores. Its behavior is parasitic yet simultaneously viral. It not only colonizes its host, it also reproduces in the host at the cellular level. its life cycle appears to be a long period of dormancy followed by accelerated activity before maturation, but I cannot establish whether it has existed on Sera since the first origins of life or it somehow developed or was introduced during human history. A successful parasite does not kill its host. Imulsion does. It may be inept, but I suspect the death of its host organisms - which appears to be every living thing on Sera, plant or animal - is part of its reproductive strategy, not an unfortunate side effect. Its high-energy content may be part of that."
—Professor Adam Fenix's research on Imulsion and Lambency.
Raw Imulsion

Imulsion in its raw state.

Besides its nature as a valuable energy source when properly processed, Imulsion also possessed a fascinating mutagenic effect. Direct exposure to Imulsion for any length of time could cause almost anything to transform into a Lambent form, making them highly aggressive, bio-luminescent and highly explosive when killed. In extreme cases, Imulsion exposure will cause the subject to mutate uncontrollably, such as the Lambent Brumak.[10]

On the death of a mutated subject that does not result in explosion, the Imulsion was seen to escape the host body and move on its own.[11]

Prolonged exposure to Imulsion, particularly in an aerosol form, was known to cause health problems in humans, chiefly the respiratory disorder called Rust Lung; Gold Rush miners had a shorter life span than the average human and many became infected.

As refined Lightmass, Imulsion was credited as being far cleaner burning and more efficient than traditional gasoline. When utilized in a generator, burned Lightmass would emit a yellowish exhaust.

Adam Fenix revealed that Imulsion was actually a living parasitic organism that mutated its host. He believed that Imulsion had properties of fungus and that the Lambent Stalks were actually Imulsion's fruiting bodies.

Behind the scenesEdit


Like "no blood for oil," Tyrus has an anti-war movement

  • In Campaign and Multiplayer, propaganda posters can be seen on walls: a picture of an upraised hand with the phrase No Blood for Imulsion. This suggests that the campus population opposed the Pendulum Wars on that basis. The phrase is also a play on the anti-war slogan "No Blood for Oil" popularized by the opposition to the 1991 liberation of Kuwait from Iraq. To find it in Gridlock, you can look by one of the spawn points right against a brick wall.
  • While petroleum exists in the Gears of War Universe, Imulsion serves as an allegory to oil throughout the series. Much of the infrastructure around the exploration, extraction, refinement, shipping, distribution, and utilization of Imulsion is similar to that of the petrochemical industry.

See alsoEdit


  1. Gears of War 3: Act I: Anchored
  2. Gears of War: Destroyed Beauty
  3. Gears of War 3
  4. Destroyed Beauty - An Inside Look at Gears of War, page 3
  5. Destroyed Beauty - An Inside Look at Gears of War, page 4
  6. Gears of War: Anvil Gate
  7. Gears of War
  8. Gears of War: Unsaid
  9. Gears of War: Aspho Fields
  10. Gears of War 2
  11. Evidenced by cutscenes in Act 4 of Gears of War 2
Enemy Types
Locust Horde
Berserker (Matriarch) · Boomer (Butcher, Flame Boomer, Grinder, Mauler, Mauler Elite, Savage Boomer, Tremor) · Drone (Beast Rider, Bolter, Cleaver Theron, Cyclops, Disciple, Flame Drone, Flame Grenadier, Grappler, Grenadier, Grenadier Elite, Gunner, Hunter, Hunter Elite, Miner, Palace Guard, Rager, Savage Drone, Savage Grenadier, Savage Grenadier Elite, Savage Hunter, Savage Marauder, Savage Theron, Sniper, Spotter, Theron Elite, Theron Guard, Theron Sentinel) · Kantus (Armored Kantus, Savage Kantus) · Sire
Hollow Creatures
Bloodmount · Brumak · Corpser (Shibboleth) · Digger · Gas Barge · Heart Leech · Kraken · Kryll · Leviathan · Mangler · Nemacyst (Ink Grenade) · Nemacyte · Reaver (Assault Barque · Hydra) · Riftworm · Rockworm · Seeder · Serapede · Siegebeast · Tempest (Shrieker) · Ticker · Torture Barge · Wretch
Former · Lambent Berserker · Lambent Brumak · Lambent Drone (Lambent Drudge) · Lambent Gunker · Lambent Leviathan · Lambent Polyp · Lambent Stalk · Lambent Wretch
Canker · Carrier · DeeBees (Bastion · Reject · Stump) · Drone (Elite Drone · Grenadier · Elite Grenadier · Hunter · Elite Hunter · Imago · Sniper · Elite Sniper) · Flock (Leech) · Hive Beast · Juvie (Screamer · Popper) · Kraken · Locust Drone · Matriarch · Pouncer · Scion (Speaker · Warden) · Sire · Snatcher · Swarmak
DR-1 · Shepherd (Deadeye) · Tracker (Shock Tracker) · Watcher (Guardian · Sentinel)
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