Gears of War Lore Explained: The Full Story From the Pendulum Wars to E-Day and the Swarm

Gears of War: E-Day finally takes the series back to the day everything went wrong. After almost twenty years of chainsaw bayonets, Delta Squad and a planet that seems to collapse a little more with every game, The Coalition and People Can Fly have gone back to the very beginning: Emergence Day, the moment the Locust Horde first clawed its way out of the ground. If you are jumping in now, or you simply never kept track of who betrayed whom across six main games, this is Gears of War lore explained from the first drop of Imulsion to the Swarm, and exactly where E-Day fits into it.

We are covering the story as the games establish it, and we clearly flag where something is developer commentary or fan speculation rather than confirmed canon. We do not spoil the campaign of Gears of War: E-Day itself beyond its officially revealed premise.

⚠️ Spoiler Warning ⚠️ This article covers the complete stories of Gears of War, Gears of War 2, Gears of War 3, Gears of War: Judgment, Gears Tactics, Gears of War 4 and Gears 5, including their endings.

⚙️ Quick Facts: The World of Gears of War

• Planet, Sera, an Earth-like world
• The resource everything revolves around, Imulsion, a glowing liquid fuel found deep underground
• The human factions, the Coalition of Ordered Governments (COG) and the Union of Independent Republics (UIR)
• The enemy, the Locust Horde, who live in the vast underground network known as the Hollow, and later the Lambent and the Swarm
• Year zero, Emergence Day, after which Sera counts its years (the original Gears of War is set 14 years after E-Day)
• Main heroes, Marcus Fenix and Dominic “Dom” Santiago, later followed by JD Fenix, Del Walker and Kait Diaz

🛢️ Imulsion and the Pendulum Wars: Sera Before the Locust

Long before anyone fought a Locust, Sera was already at war with itself. The planet went through a crippling energy crisis until Imulsion was discovered, a powerful liquid that could be refined into fuel. It solved the crisis but created a new problem: whoever controlled Imulsion controlled the world’s economy. The rivalry between the nations of the Coalition of Ordered Governments and the Union of Independent Republics turned into the Pendulum Wars, a conflict that raged for 79 years and killed millions. The name fits, because the advantage swung back and forth for decades without either side landing a decisive blow.

The war finally ended thanks to the Hammer of Dawn, a network of orbital satellites that can fire devastating laser strikes at any point on the surface. Marcus’s father, the scientist Professor Adam Fenix, completed the system, and after its destructive power was demonstrated the UIR surrendered. Remember that weapon, because it shapes the fate of Sera far more than any Lancer ever will.

The Pendulum Wars also left deep personal scars on our two heroes. Dom’s older brother, Carlos Santiago, was killed at the Battle of Aspho Fields, where Marcus earned the Embry Star, one of the COG’s highest military honors. Marcus later left that medal on Carlos’s grave. That shared loss is the foundation of the brotherhood between Marcus and Dom, and it is exactly where Gears of War: E-Day picks up their story.

💥 What Is Emergence Day? The Locust Invasion Explained

Only about six weeks after the armistice that ended the Pendulum Wars, with a war-weary population trying to return to normal life, the ground opened up. On Emergence Day, the Locust Horde burst out of the Hollow beneath the planet’s surface and attacked human cities across Sera at the same time. Humanity had no idea this enemy even existed. Within the first 26 hours, roughly a quarter of Sera’s population was dead.

The Locust are a militarized subterranean species led by a queen, with grunt soldiers called Drones, towering Boomers, and enormous beasts such as the Corpser, the Brumak and later the Riftworm. Their goal looked simple: wipe out humanity on the surface. Why they attacked, and why exactly then, is one of the biggest mysteries of the original trilogy, and the answer only arrives later in the series.

🔥 The Hammer of Dawn Strikes and the Fall of Sera

The war against the Locust went badly from the start. Humanity’s last real refuge was the Jacinto Plateau, home to the COG capital Ephyra, because it sits on granite bedrock that the Locust could not tunnel through. Around a year after E-Day, Chairman Richard Prescott made the most infamous decision in Sera’s history. He gave civilians three days to make their way to Jacinto, then turned the Hammer of Dawn on humanity’s own cities to deny them to the Locust.

The strikes burned most of the planet’s surface and killed countless people who could not or would not leave. Those who survived outside Jacinto and refused to live under the COG became known as the Stranded, scavengers who never forgave the government for what it did. The scorched-earth campaign forms the backdrop of Gears Tactics, which is set about a year after E-Day.

⚔️ The Locust War: Gears of War Story Recap From Judgment to Tactics

Two prequels fill in the early years of the war. Gears of War: Judgment (2013) follows Damon Baird’s Kilo Squad, with Augustus Cole, Sofia Hendrik and Garron Paduk, during the first weeks after E-Day. Their story is told through testimony at a military tribunal, after the squad used an unauthorized Lightmass Missile against the Locust commander Karn.

Gears Tactics (2020) is set roughly a year after E-Day and follows Sergeant Gabriel “Gabe” Diaz and Major Sid Redburn, who are sent to hunt down Ukkon, an immortal Locust scientist who breeds the Horde’s monsters. Along the way they meet Mikayla Dorn and rescue Reyna Torres, a prisoner who recovers her mother’s amulet. The game also drops the first big hint about where the Locust came from: Redburn reveals that he once worked at New Hope, a COG research facility whose experiments to cure the disease known as Rustlung went horribly wrong. Gabe and Reyna would later become the parents of Kait Diaz, which is far more important than it seems at first.

Gears of War: E-Day shows the very first hours of the Locust invasion on the streets of Sera.

🧱 Gears of War Story: Marcus Fenix, Delta Squad and the Lightmass Bomb

About ten years after E-Day, during a Locust assault on Ephyra, Marcus Fenix abandoned his post in a desperate attempt to save his father. Adam was believed dead, and Marcus was court-martialed and sentenced to 40 years in prison. Gears of War (2006) begins 14 years after E-Day, four years into that sentence, when Dom breaks Marcus out of Jacinto Maximum Security Prison because the COG needs every soldier it can get.

Marcus joins Delta Squad alongside Dom, Damon Baird and Augustus Cole, with Lieutenant Anya Stroud guiding them over the radio and Colonel Victor Hoffman in command. Their mission is to map the Locust tunnels so that the Lightmass Bomb can destroy the heart of the Horde. Lieutenant Minh Young Kim and the rookie Anthony Carmine do not survive. The Resonator, which was supposed to map the tunnels, fails, so Delta recovers the missing data from Adam Fenix’s old laboratory. On a Locust train, Marcus and Dom kill General RAAM and deploy the bomb. It looks like victory, until the voice of the Locust Queen makes clear that the war is far from over.

🌊 Gears of War 2: The Hollow, Queen Myrrah and the Lambent

Gears of War 2 is set six months later. The Locust have survived and are now sinking entire human cities, including Tollen and Montevado, using a gigantic Riftworm. Jacinto is next. The COG goes on the offensive and sends thousands of Gears into the Hollow. Delta kills the Riftworm from the inside, though Anthony’s brother Ben Carmine dies in the process.

Gears of War 2 is also the most personal chapter for Dom. He has spent years searching for his wife Maria, and he finally finds her in a Locust prison camp, tortured into a vegetative state. He ends her suffering himself. Delta also rescues their old comrade Tai Kaliso, who was tortured by the Locust general Skorge and takes his own life soon afterward. In the Locust capital of Nexus, Delta finally meets the queen, Myrrah, who looks entirely human. The squad also learns why the Locust attacked in the first place: the Hollow is being overrun by the Lambent, creatures mutated by Imulsion, and the Locust are fighting for their own survival. To destroy the Horde, the COG deliberately sinks Jacinto and floods the Hollow. After the credits, a voice on the radio reveals that Adam Fenix is still alive.

Delta Squad as seen in Gears of War: Reloaded, the 2025 remaster of the game that started it all.

☢️ Gears of War 3 Ending Explained: Adam Fenix and the Countermeasure

By Gears of War 3, the COG has collapsed. Survivors have fled to the island of Vectes, and the Lambent are spreading on the surface. Chairman Prescott reappears aboard the carrier CNV Sovereign, but is mortally wounded in a Lambent attack. Before he dies, he hands Marcus a data disc revealing that Adam is alive and held on Azura, a secret island hidden behind an artificial hurricane and now occupied by Myrrah. During the journey, Dom sacrifices himself at the Imulsion town of Mercy to save his squad, one of the most memorable moments in the series.

On Azura, Adam finally reveals the truth. Imulsion is a living organism, a parasite that spreads through living beings and turns them Lambent. Adam admits he had worked with Myrrah before E-Day to stop the Lambent and keep the Locust underground, but they ran out of time. His solution is the Imulsion Countermeasure, a weapon that destroys every cell infected with Imulsion. To test it, he had infected himself. When the Countermeasure activates, Adam disintegrates, the Lambent turn to dust, and the Locust crystallize. A surviving Myrrah mocks Marcus’s loss, and Marcus kills her with Dom’s knife. The Locust War is over.

🐛 Gears of War 4 and Gears 5: The Swarm and Kait Diaz

Gears of War 4 jumps 25 years ahead. The Countermeasure left Sera free of Imulsion but plagued by violent storms called windflares, and a rebuilt COG under First Minister Jinn keeps its people behind city walls. Outside, the Outsiders live freely. The new heroes are JD Fenix, the son of Marcus and the late Anya Stroud, his friend Del Walker, and Kait Diaz, the daughter of the Outsider leader Reyna. When villages start disappearing, they discover the Swarm, a new enemy that has grown out of the crystallized Locust and uses captured humans to create new soldiers. Kait finds her mother fused into a Swarm hive and, at Reyna’s request, ends her life. Reyna’s amulet bears a symbol that looks like Myrrah’s emblem.

Gears 5 resolves that cliffhanger. In a secret COG laboratory beneath Mount Kadar, Kait meets an AI version of the scientist Niles Samson. He reveals that Myrrah was once a child test subject at New Hope, immune to the effects of Imulsion, and that the Locust were created by combining the DNA of the Sires, the horribly mutated results of New Hope’s experiments, with Myrrah’s embryonic stem cells. Myrrah had a daughter, Reyna, which makes Kait the granddaughter of the Locust Queen. Samson’s real goal is to bring Reyna back, and he succeeds: she rises as the new queen of the Swarm. During her attack on New Ephyra, Kait must choose between saving JD or Del, while the COG once again fires the restored Hammer of Dawn.

🏙️ Gears of War: E-Day Story: Where the Prequel Fits

That brings us back to the beginning. Gears of War: E-Day launched on October 6, 2026 for Xbox Series X|S and PC, with day one availability on Game Pass, and is set 14 years before the first game. The Coalition is not telling a globe-spanning story this time. The campaign stays in a single city, Kalona, home to an Imulsion refinery, and covers the first days of the invasion. Marcus and Dom are struggling with civilian life after the Pendulum Wars and still carry the memory of Carlos when the tremors start and the Locust emerge.

They are joined by Mags Carter, a former Gear now working at Kalona’s Imulsion refinery, and Lucas Reyes, a young communications officer with no frontline experience. Together they form Bravo Squad. Tai Kaliso, whose tragic fate fans already know from Gears of War 2, also appears. Marcus is once again voiced by John DiMaggio, and Dom by Carlos Ferro. If you want to know more about the launch, editions and PC requirements, read our report on Gears of War: E-Day going gold.

Bravo Squad, with Marcus Fenix and Dom Santiago, fights to survive the fall of Kalona in Gears of War: E-Day.

🔍 Canon vs Speculation: What We Know and What We Don’t

E-Day lands on top of a story that is already known to be full of secrets. Canon established by Gears of War 3 says that Adam Fenix knew about the Locust before Emergence Day and had worked with Myrrah. Canon from Gears Tactics and Gears 5 says that the Locust were born from COG experiments at New Hope. In other words, the government Marcus and Dom serve was involved in creating the very enemy that is about to destroy their world.

Many fans are therefore theorizing about whether E-Day will show signs of that cover-up, hint at Adam’s secret work or even feature Myrrah herself. These are fan theories, not confirmed details, and we are deliberately not spoiling the actual campaign here. Whatever the answers are, E-Day gives players the chance to see the beginning of a war whose dark origins long-time fans already know.

❓ Quick Questions About Gears of War Lore

What is E-Day in Gears of War?
Emergence Day is the day the Locust Horde emerged from the Hollow and attacked human cities across Sera, only about six weeks after the end of the Pendulum Wars. Sera counts its years from that day.

Who are the Locust?
The Locust are a subterranean species led by Queen Myrrah. Gears Tactics and Gears 5 reveal that they were created through COG experiments at the New Hope Research Facility, using Sire DNA and Myrrah’s stem cells.

Why did the Locust attack humanity?
The Hollow was being overrun by the Lambent, creatures mutated by Imulsion. The Locust were fighting for survival and wanted to take the surface for themselves.

Who is Carlos Santiago?
Carlos was Dom’s older brother and Marcus’s close friend. He died during the Pendulum Wars at the Battle of Aspho Fields.

Is Kait Diaz related to Queen Myrrah?
Yes. Gears 5 confirms that Kait’s mother Reyna was Myrrah’s daughter, which makes Kait Myrrah’s granddaughter.

In what order should I play the Gears of War games for the story?
By in-game chronology: Gears of War: E-Day, Gears of War: Judgment, Gears Tactics, Gears of War (or Gears of War: Reloaded), Gears of War 2, Gears of War 3, Gears of War 4 and Gears 5. For first-time players, release order still works perfectly well.

Final Words

Gears of War has always been a story about soldiers fighting a war that was lost long before they arrived. Imulsion, the Hammer of Dawn and the secret experiments at New Hope were all decisions made long before Marcus first picked up a Lancer. Gears of War: E-Day finally shows the moment the consequences came to the surface, and knowing the full story makes that first day hit even harder.

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Picture Source: Xbox Game Studios, The Coalition, Gears of War: E-Day on Steam, The Coalition, Gears of War: Reloaded on Steam