Gears of War/Act One: Ashes

Gain Entrance to the House of Sovereigns
Here you want to flank to the right and take out the Grenadier and get into the hallway. Take the Frag Grenades he drops, you'll need them. Work your way around to take out the Troika Drone Gunner, close the Emergence Hole on your way with your new found Frag Grenades.

Once those waves are clear, enemies approach from the rear. Take them out with the Troika and then continue inside to finish off the Locust inside the House of Sovereigns entryway. Once inside and clear, Kim will open the door.

Save The Alpha Squad Soldier
Once inside the House of Sovereigns, you will hear some survivors of Alpha Squad having a good time fighting off the Locust. As you approach you notice it's a lone squad member of Alpha Squad and he needs help. Ward off the Locust to save him, his name is Augustus Cole. He tells you of the radio transmissions being jammed by the Seeders and the rest of his squad is off safe in Tomb of the Unknowns.

Destroy All Seeders
You reach a door you need Jack to open, so he de-cloaks and begins his work. While he works the squad is attacked by a large group of Wretches, they come from both sides so be sure to find a safe yet open spot.

After you progress you will find the new weapon, The Hammer of Dawn, this weapon will be used against the Seeders. As you walk outside, you will find your first seeder. Focus and hold the Hammer's beam on the Seeder to toast it. Then feel free to use the beam on the remaining Locust.

As you progress back into the house, you will find another Seeder to take care of. Let your squad exterminate the Locust while you finish off the Seeder with The Hammer of Dawn. If you dropped it since the last Seeder battle, there is another to be found in the room.

After that Seeder is eliminated you can call up Anya to let her know your status on attempting to reach the rest of Alpha Squad. The communication is not great yet, which means a Seeder is still in the area.

Search For Alpha Squad
Clear through the Sanctuary here and reach the third and final Seeder. Take it out so you can get in touch with Anya and Alpha Squad. You find out that Alpha Squad is okay, but currently pinned down by Troika's on the rooftop of the House of Sovereigns.

As you come to the end of the hallway, on the left will be another Troika mounted at the end of the hallway. Roadie Run out into the hallway and into the doorway on the left. Follow this around, take care of some Wretches, and come up behind the Gunner and do with him as you please.

Continue on and clear out a room full of Locust. Also there is lots of ammo to be picked up in this room once it is clear, so I'd do that. You can now continue on to the rooftop to help out Alpha Squad.

Secure the Landing Zone For Evacuation
Take out the Gunners here and get into their Troika's to clear out all the Locust on the ground outside of the Tombs. Once you do this, you can signal ahead to clear out Alpha Squad.

Continue the Single-Player Walkthrough in Tomb of the Unknowns