im tired to see people complaining about the storyline . GeoW story line is a " Donnie Darko " type of storyline , where you need to put every piece together trying to figure out what going on ( and GeoW is a trilogy , so you will find out more in the other games ) .

here a Q/A post made by a GeoW fan :
http://gearsforums.epicgames.com/showthread.php?t=557716
---MAJOR SPOILERS---
Please, if you have not played gears of war, do not read this. I mean come on, your being silly if you dont want spoilers but clicked on this thread, plot writeup is a writeup of the plot!!!
---MAJOR SPOILERS--

[spoiler]
Story of Gears of War
So, I got bored doing homework, and wrote this guy up. Let me know if it is helpful!!!

Dom breaks Marcus Fenix out of prison
• Q. Why was Marcus Fenix imprisoned?
• A. During the Locust Assault on Jacinto, Marcus broke off from squad in attempt to save father at the East Barracks. Marcus was too late, as the Locust had overrun the position and father was killed. Post-op, Marcus Fenix was charged with Cowardice and Dereliction of Duty, and sentenced to life.
Regroup with Squad
Get orders to regroup with Alpha Squad (have resonator)
• Q. What’s the deal with this Resonator?
• A. The COG have created a new offensive plan to assault the Locust underground position. They will use the Resonator to gather Locust Tunneling data, which will be used to guide the LightMass Bomb to a central position.
• Q. LightMass Bomb?
• A. LightMass is the process in which a portion of Imulsion is converted to pure energy. So, presumably this LightMass Bomb is used to convert the Imulsion around it into pure energy, i.e. the bomb part.
• Q. What the hell is Imulsion?
• A. Imulsion is the phosphorescing (glowing) liquid which replaced hydrocarbons (kerosene) on Sera 79 years ago. It was discovered by Dr. Helen Cooper, and it is important to note the Pendulum Wars were fought because of Imulsion reserves.
Find downed Alpha Squad Members
Link up with Cole from Alpha Squad
Terminate Com Jammers
Link up with rest of Alpha Squad with Resonator
Get orders to get to the Imulsion Processing Facility
• Q. Imulsion Processing Facility wha?
• A. We have to drill for oil today right? So, where do you think they got Imulsion? Remember that the Lightmass Process only converts a portion of Imulsion into energy, to this facility presumably separates, refines, and packages the Imulsion into usable energy for Sera.
• Interesting Note: The squad does comment that extended exposure to imulsion will cause you to phosphoresce (remember the glowing wraiths?). So, it is logical that Sera doesn’t use straight up imulsion for it’s energy, thus the processing facility.
Evac chopper downed by Locust
Find alternate route to Imulsion Processing Facility
Go to “Stranded” encampment to retrieve vehicle
• Q. Why are we linking up with Stranded?
• A. Well, the Extraction chopper that WAS going to get your ass to the Imulsion Processing Facility was shot down, remember? Dom gets the bright idea to call in a favor from a Stranded to get a vehicle, so that they can still get to this IPF.
Move through nighttime urban area to vehicle
Take vehicle back to encampment, fend off Locust Assault
Move to Imulsion Processing Facility in Vehicle
Move through facility
Move to Resonator detonation point through underground caverns
Cole retrieves autonomous mapping bot
• Q. So why the hell was there this little machine just sitting down there?
• A. Well, we don’t have the “from the horses mouth” answer to this question. But, there are some theories as to why.
o Imulsion is valuable, its only logical that the facility was using these bots to map out the Imulsion reserves.
• As far as Fenix Senior is concerned, I’m sure that noone at [insert place name here] was just sitting on their ass, so he could have worked for the COG to find more Imulsion.
o Before E-Day, citizens were probably exploring these caverns.
o Fenix Senior could have been working on exploring these caverns covertly. He obviously wasn’t buddy buddy with the COG if he had to hide his lab from them. As a scientist, he might have been exploring out of curiosity, he could have been looking for how extensive the Locust Tunnels are.
o Important to Note: His position was overrun, and since he didn’t have all the data, he had not submitted his data to the COG. The COG knew nothing of the data until Cole found the bot.
Alpha Squad detonates Resonator, moves to surface
Command relays that information gathered from resonator was not enough
• Q. Why didn’t the resonator work?
• A. Well, imagine the COG with a very powerful ultrasound machine, listening to the ground. Imaging several of these all around [insert place name here]. Now, an ultrasound machine shoots out sound and gets the data bouncing back, and forms that into an image. That’s what the Resonator was supposed to do, provide the sound for the COG to map the tunnels with sound. But, since the tunnels were much more extensive than previously thought, the resonator fell short.
• Important Note: Who here has seen Jurassic Park? In the second scene the paleontologists stick a shotgun shell into a big rig firmly planted on the ground, and fire the shell into the ground. They then got an image back. Same thing here, but with a big bomb.
Cole has Autonomous Mapping Bot hacked, reveals extensive, but incomplete, locust tunneling data
Command orders group to move to Fenix Estate, where the AMB originated from
• Note: See the Q & A of the AMB bot’s finding for stuff about this.
Alpha Squad moves to Fenix Estate
Explores estate, finds lab
Lab contains complete tunneling data
Command orders Alpha Squad to rendezvous with Lightmass Bomb and upload tunnel data
• Q. Why is the lightmass bomb on a train?
• A. Its there so that they can send the train along the tracks, until it gets to a point where imulsion is at the surface, and the train falls into the imulsion.
• Q. Why do they have to upload targeting data to the Lightmass bomb?
• A. So that it can find targets for its little lightmass cruise missiles to hit.
• Q. Did the lightmass bomb detonate the imulsion around it?
• A. Probably not, because only a portion of the imulsion is converted to energy. It is more likely that each of the little missiles were loaded with the convertible energy portion of imulsion, and they then release their onboard energy. They are probably just using the imulsion as a way to get to the Locust Tunnels. Note that it is not the imulsion which explodes in the scene, but the lightmass bomblets. Though, the imulsion around it did ignite, as evidenced by the Corpsers being burnt in their tunnels…
Alpha Squad retrieves and repairs APC and moves to rendezvous point
Half of Alpha Squad gets to the train
Uploads targeting data
King Raven extracts Alpha Squad
Lightmass bomb moves through Locus tunnels and detonates

Cole retrieves autonomous mapping bot
• Q. So why the hell was there this little machine just sitting down there?
• A. Well, we don’t have the “from the horses mouth” answer to this question. But, there are some theories as to why.
o Imulsion is valuable, its only logical that the facility was using these bots to map out the Imulsion reserves.
• As far as Fenix Senior is concerned, I’m sure that noone at [insert place name here] was just sitting on their ass, so he could have worked for the COG to find more Imulsion.
o Before E-Day, citizens were probably exploring these caverns.
o Fenix Senior could have been working on exploring these caverns covertly. He obviously wasn’t buddy buddy with the COG if he had to hide his lab from them. As a scientist, he might have been exploring out of curiosity, he could have been looking for how extensive the Locust Tunnels are.
o Important to Note: His position was overrun, and since he didn’t have all the data, he had not submitted his data to the COG. The COG knew nothing of the data until Cole found the bot.
Alpha Squad detonates Resonator, moves to surface
Command relays that information gathered from resonator was not enough

The little bot was called a geobot correct?
But Baird was looking for a geobot to fix the car.
Why the hell would somehting that is used in cars have maps?

Oh and the reason that it was down there in the caverns was explained in act 1. Remember right before the first troikia turret, when Carmine was still alive he had it in his hands off of the dead alpha soldier? kim asked him if it was the resonator, he said no, and then Carmine threw it down the emergence hole. they made a big deal of it. [/spoiler]


And there also alot of theories going around about the queens, about who are the locust , and WHY the the planet Sera . here an exemple :
http://gearsforums.epicgames.com/showthread.php?t=556656
My theory does not take up a page or have vivid details, but it makes sense. In the interview Qs with Eric Nylund, they ask what planet Sera is and where is Earth? He replies by saying it's a secret and it will be revealed in time. Now obviously the story behind the Locust Horde has something to do with Imulsion. Here on Earth there are wars for OIL and a motto that goes "NO BLOOD FOR OIL!" Now in GOW you know about the Pendulum Wars over the newly discovered Imulsion fuel source. You also see a repetitive poster that says, "NO BLOOD FOR IMULSION!" Here's the idea: A nuclear war eventually covered most of the planet Earth. Thus transforming and mutating a portion of the people, and others survive unaffected. The other race eventually becomes the Locust Horde. They know that war for fuel caused all the damage that they now live with and they want to prevent it before the wars completely destroy the planet (maybe newly named "Sera") and their race/civilization.
Keep this in mind and guess what I just looked up; Sera is a district/town near or in Hiroshima, where the atomic bomb was dropped. Atomic bomb, mass death, afterwards of a nuclear bomb, just like I just suggested in my theory. And toexplain why they want all humans dead, maybe they know that all humans will do is fight because of greed, when the Locust stand united because they have learned it is the only way of peace.
Another support of this theory is the train level in act 5. I know the sky is supposedly covered in the Locust, but what if that is just a result of radiation. And look at the destroyed land all around them. Another thing supporting my theory was when the Hivemind lady said "they ultimately did what they do best, destroy" DESTROY!!!

But reviewers only seem to see the story of a alien invasion :? quite sad :( Spread the story :D