Each chapter switches back and froth from the past to the present. In the past story line, it tells the tale of Marcus starting public school at the age of 10. He is quickly bullied because a rich background. Carlos Santiago comes to Marcus's defends and the two become close friends. Carlos introduces Marcus to his little brother Dom and the rest of his family, where Marcus spent most of his time. They family would deem Marcus a honorary Santiago. Marcus would become more then a friend to Carlos and Dom, he had becomes a brother.
Marcus was drawn to the closeness of the Santiago's. The Fenix's where never a close family also putting work first. Marcus never felt a real close to his Father Adam Fenix as he was always away or to busy working on projects for the COG. At a young age Marcus's mother disappears which put a even more distance between him and his father.
“I shall remain vigilant and unyielding in my pursuit of the enemies of the Coalition.
I will defend and maintain the Order of Life as it was proclaim by the Allfathers of the Coalition in the Octus Canon.
I will forsake the life I had before so I may perform my duty as long as I am needed.
Steadfast, I shall hold my place in the machine and acknowledge my place in the Coalition.
I am a Gear. ”
After finishing school, Carlos and Marcus join the COG army. Shortly after that, 16 year old Dom joins the COG special forces commandos after finding out his girlfriend and soon to be wife Maria is pregnant. Dom is trained by a rough neck women by the name of Bernie Mataki. While Dom is in training camp, Carlos and Marcus are deployed and Marcus is slowly making a name for himself.
Soon after plans start forming for Operation Leveler. Operation Leveler is a covert assault on a research facility located at Ashpo Fields owned by the other super power of Sera, the Union Of Independent Republics. The UIR are developing a super weapon called the Hammer Of Dawn. Dom unit of commandos are chosen to infiltrate the base, while the COG army, including Carlos and Marcus, surround the base to protect and stop any attacks from the UIR trying to stop the raid.
Major Hoffman led the commandos in the raid. As they where getting the plans for the Hammer Of Dawn, a security guard that was knocked unconscious when the commandos breached the facility woke up and alerted nearby reinforcements. The COG army is then quickly attacked. In the mist of the battle the commandos get the information they came for and make there escape. Marcus, with some quick thinking, buys the commandos more to make that escape.
"You dumb bastard. You're the best. Can’t let you make a dead asshole out of yourself."— Carlos's final words to Marcus before he managed to pull the pin on his grenade and kill himself
In the fire fight Carlos makes a mistake trying to take out a enemies tank costing the life's of a couple of fellow squad members. Carlos is then wounded bad buy tells no one, he continues to give Marcus cover as he takes out the remaining tanks. As Bernie and Marcus try to make there way to Carlos, he tells them that they are wasting there time and to just leave him. Feeling guilty for getting squad members killed, he did not want to be reasonable for more deaths, especially for Marcus's. They come anyway as more UIR units start to flood a bridge that Carlos was next to. Carlos then pulls a pin on a grenade blowing up himself and the bridge along with him cutting off the UIR and giving the COG more time to escape. Bernie and Marcus would cover up the mistake that Carlos had made. Carlos would be awarded the Embry Star(awarded for heroism and is the highest possible honor a COG soldier can be awarded) for his sacrificing himself to blow the bridge. Dom would give the Embry Star to his parents.
The present story line takes place a week after the end of the first game when they set off the Lightmass Bomb down deep in the Locust's tunnels. Out on a patrol, Delta Squad in the middle of a battle with the Locust, they find Bernie Mataki. She was long thought to be dead after being missing for years after the Locust first attacked on Emergence Day. She quickly gets back into the military life by joining Delta Squad.
With Bernie back Dom starts questioning her about Carlos's death. Never getting a full story of what happen that day from Marcus, Dom hoped to get one out of Bernie. She tries avoiding the the subject as much as she can. As this is going on, Delta Squad gets orders to head to North Gate. North Gate is used to supply the last major human city Jacinto with food. The COG finds out that the Locust are heading to North Gate to try and cripple the humans by destroying that food supply. They quickly organized a contingency plan to transport all the supplies and equipment from North Gate and get it all to a new safe location.
Aspho Fields gives you more of the life before the Locust. Also giving you more back ground on Marcus and Dom. You really understand there closeness from growing up together, and the lost of there brother Carlos. You get more a understanding of why Hoffman has so much anger towards Marcus. I also like the little bit of the Pendulum Wars that is told through the battle at Aspho Fields. The next book in the series is Gears Of War: Jacinto's Remnant.