Gears of War 3 - Abandon Ship

Head straight down the hall and take a left at the end. Tip a table and take cover. Stay back and take out the lambent from here. At the end, go right and talk to the people moving the vending machine and through the door at the left.

The next room is rather open. You have quite a few lambent strait ahead. Find some cover and try to pick a couple off but also watch the catwalk up above and to the right. The left side of the room is a pretty save place to be and gives you a good angle for flanking. Take out the Drudge and the lambent grubs and drop down. Follow the path to come to the first Deck lift.

The Raven pilot will mention that you need to raise the lift and soon after you will be attacked by glowies from the right. Unfortunately, they've got a slight height advantage so you should try and get up the stairs as soon as you can to get some good cover. Once they are cleared out, go past the door they came through and up the stairs to the catwalk. Follow it to the control room to raise the lift.

Exit the control room and go down the stairs to your right. Just after you talk to the next Raven pilot, the chopper gets destroyed and you have to shoot a tentacle and defend against polyps. Destroy those and some glowies will bust out of a door to your left (similarly to how they did by the other lift). Kill them and head up the stairs again. Go to the control room and activate this lift too. You'll get on the lift automatically.

At the top of the lift, you need to kill a drudge and then turn off a valve behind him and to the right to clear the flames. Round the corner to the right and take out the moderately sized lambent group. Just behind them is another valve. Head back the way you came and take your first left across the area that was just on fire. Watch the person get blown up and then use their extinguisher to cross the flames.

After you get to look the Leviathan in the eye, you'll slide away and end up in engineering. Follow the path and bust down the door. In the next room you'll be attacked by some lambent grubs. Kill them and then the polyps after, but don't bother with the tentacle. Keep killing glowies until a piece breaks off from the upper level, creating a ramp upward.

At the top, go left to find a door. Go through the door, up to the deck and then run as fast as you can across so you don't get smashed by the crates. Open the door to your right to get a silverback. Just before you jump in, there is a collectable on the table to the left. Take the silverback right and through the gate. Move right along the deck to watch a guy get chomped on by the leviathan. Start shooting him in the eye until it bursts. When it does, he'll back off and you'll have to fight a wave of glowies. Kill them and he'll return. Shoot him in the same eye you were shooting him in before. You'll get another wave and then you'll have to dislodge him from the ship one more time.

And then he blows up.