- "I have discovered a way to end the war, once and for all."
- —Adam Jonathon Fenix revealing the countermeasure's existence
The Imulsion Countermeasure Weapon was a targeted radiation weapon that could destroy all Imulsion cells in any living being. It was created by Adam Fenix to stop the Lambent Pandemic that was sweeping across Sera. Queen Myrrah hoped to use the weapon to save the Locust race and destroy both the Human race and the Lambent.
Meeting Adam Fenix
Four years before E-Day, Queen Myrrah of the Locust Horde contacted Adam Jonathon Fenix to construct a device that could wipe out the Lambent, who were killing the Locust underground. If he did not do this, she threatened to invade the surface and destroy the human race. Adam, always being locked in his study, was determined to find the answer. However, four years later, the Locust were dealt a serious blow in the Lambent War and had no choice but to invade the surface of Sera. Adam knew of E-Day, but kept it secret so he could continue his work on the project and avoid being executed.
Kidnapped to Azura
After Adam admitted the truth to his assistant, Nevil Estrom, he told Chairman Richard Prescott, who had Adam abducted to the secret island of Azura where he continued his research on stopping the Lambent and Imulsion which he realized was a parasitical organism and the cause of Lambency. Adam worked with biologists and other scientists on finding a cure to Lambency, but when that continued to fail, he started thinking in terms of killing it. Remembering what his wife had said about using radiation to kill cells infected with various pathogens at the University she worked at, Adam struck upon the idea of using radiation in some manner to kill Imulsion and began working on the weapon.
Building the Weapon
By 17 A.E., Adam had nearly completed the weapon which was built on top of Pinnacle Tower. When word of the Queen's Guard being spotted at Endeavor Naval Shipyard reached Azura, Adam was working on the weapon and told Richard Prescott that he was close to finishing it, but perhaps not close enough if the Locust were coming. However, Adam noted that it wouldn't be the first time he'd built a weapon of mass destruction under a deadline. Adam stated that the device would effect the Locust depending on their degree of Imulsion contamination and brushed off concerns about his own level of contamination.
As the danger from the Locust increased, Adam focused solely on getting the weapon operational. As it wasn't portable Adam was insistent that they needed to defend it until the weapon could be used to destroy the Lambent.
First Battle of Azura
A little over a month after the Locust were spotted at Endeavor, they attacked Azura and Captain Paul Dury ordered Red Squad to defend Adam and the device. Adam and Nevil Estrom managed to reach Pinnacle Tower and the weapon to defend it with Red Squad against the attacking Locust forces. Richard Prescott and Dury eventually arrived and ordered Adam to evacuate, but he refused as he knew there was no point in saving him if they abandoned the weapon as well. Knowing the Queen Myrrah needed him, Adam chose to stay on Azura to finish it and sent Prescott to find Colonel Victor Hoffman for help and sent Nevil to hide his research in one of the limestone caverns so the weapon could be rebuilt if he was wrong about Myrrah's intentions.
Completing the Weapon
Instead of killing everyone as she planned, she found Adam (who she believed was dead) and spared only him to continue his research. Adam found a way to use targeted radiation to kill Imulsion and all Lambent lifeforms, but while humans not severely infected wouldn't die, the Locust would due to their level of exposure (which was stage three, muscle pains and fevers). Adam wanted to help the Locust, however the Imulsion was reaching a critical point in its lifecycle. If Adam attempted to fix the weapon to make it harmless to the Locust, it would not work. Adam left his lab when the guards were changing shifts to compile his data. However, he was eventually caught by a guard and the guards around his lab were tripled.
Second Battle of Azura
- "Think of it as a neutron bomb without the blast, one that only kills Lambent cells... in all of us."
- —Adam Fenix, explaining to Damon Baird how the Countermeasure works
During the Second Battle of Azura, Marcus Fenix, along with Delta-One, found Adam and they escorted him to the roof of Pinnacle Tower. There, Delta fought off the Tempest so Adam could activate the weapon. They succeeded in defeating the Tempest with the Hammer of Dawn. However, Adam then revealed he too will die, because he injected himself with enough Imulsion that he too would perish. When asked why, he said he had to test the weapon first. He died, but not before telling his son to live his life and that he loved him. All of the Locust and Lambent were destroyed and Myrrah was stabbed by Marcus with Dominic Santiago's commando knife.
After the mass Locust extinction, Locust corpses began to form an impenetrable crystal shell around their bodies. They were dumped in mass graves underground. A few Locust managed to survive the firing of the weapon, but they were hunted down and killed by the Brash Brigade.
Around 42 A.E., the Locust began to emerge from their crystal shells and formed the Swarm. It is also shown that the weapon only destroyed the Lambent as all Lambent organisms were vaporized by the weapon, unlike the Locust.
- Dirty Little Secrets
- Gears of War 3 (First appearance)
- Aftermath (Mentioned only)
- Ephyra Rising (Mentioned only)
- Gears of War 4 (Appears in flashback(s))
- Gears 5
- Gears: Hivebusters (Mentioned only)
- Hivebusters (Mentioned only)