Emergence Day/Gears of War 1
The world of Gears of War has always known war. The largest was the war between the Coalition of Ordered Governments and the Union of Independent Republics, which lasted for nearly 80 years over the near unlimited energy resource of Imulsion. That war ended when the COG managed to snag the orbital laser weapon known as the Hammer of Dawn to lay waste to UIR cities, at which point treaties were signed and the COG became the largest form of government on Sera. Unfortunately for them, the peace was short lived, as the Locust rose from the ground and wiped out most of the human population on what later became known as Emergence Day. To deny the Locust any advantages, the COG used the Hammers of Dawn for a scorched earth policy, leaving only Jacinto Plateau as the last stronghold against the underground monsters. Anyone not evacuated became known as the Stranded.
A decade after E-Day, protagonist Marcus Fenix left his post at the Battle of Ephyra to save his father Adam, who was a lead researcher in studying the Locust. He wasn’t able to save Adam, and was later court martialed and sentenced to 40 years in prison. Four years into that sentence, his childhood friend Dom Santiago comes to bust him out of prison to help him and Delta Squad deploy the Lightmass Bomb, which the COG believes can destroy the Locust. But before they can do that, they need to find the Resonator, which will let them map out the underground Hollow that the Locust live in and was last in the possession of Alpha Squad. Led by Minh Young Kim, Delta Squad later acquires former Thrashball player Augustus Cole of Alpha Squad, who leads them to Alpha. No sooner than they reunite do the Locust show up, and Kim is killed by General RAAM. After killing a Berserker, Marcus is promoted to Delta’s leader and leads Dom, Cole, and fellow Alpha survivor Damon Baird to a mining facility to deploy the Resonator.
Unfortunately, it turns out that it can’t provide data on the entire Hollow, so Delta heads to Marcus’ childhood home, where the full data is in Adam’s lab. They managed to get the data, kill a particularly nasty Brumak, and hitch a ride on a train that’s holding the Lightmass Bomb. But first, they have to get through RAAM, who they successfully kill, and the Bomb hits the Hollow. The tunnel networks are destroyed, but Locust Queen Myrrah says that this is nothing but a setback, and vengeance is coming.