Mass Effect 2/The Price of Revenge

Welcome to the Jungle
To help Zaeed tie up some loose ends, head to the planet Zorya out in the Ismar Frontier. Upon landing, follow the valley path, investigating some bodies along the way. When the path opens up, take cover from the Blue Suns mercs that litter the area. Picking them off with long-range weapons is the safest way to go here. When the mercs are gone, a few more will show up as reinforcements (including a heavy). Finish them off then check the area for a med kit.

Continue across to the bridge and activate the controls. Zaeed will stop you here and reveal the real reason he brought you here — he's after Vido Santiago, head of the Blue Suns. The two started the Blue Suns together and, to show his kindness, Vido shot Zaeed in the head. Somehow managing to survive, Zaeed's been out for blood ever since. Once you've regained control, cross the bridge and follow the path around (stopping to pick up some palladium) and open the refinery doors. Once inside, the old friends will have a little chat of which Zaeed tires quickly, starting a fire that quickly spreads throughout the entire facility.

Zaeed will try to justify his actions here by telling you it was necessary. You can chide him for it or, with the right conversation choices ("That was unnecessary."), get a Paragon interrupt and punch him in the face for being stupid enough to light up the refinery. Either way, head out through the newly opened door and take out the two mercs beyond. Check the area for more palladium then open the next door. Here you'll be faced with a choice, ignore the refinery workers and hunt Vido no matter the cost, or save the workers first and hope you can still catch up to Vido.

Find Vido Santiago
If you've chosen to ignore the workers, head through the door here and hurry to cover. There are a few thugs lying in wait here. Take them out and head around the corner and in to more cover. Beyond the next door lies a research terminal with an Assault Rifle Damage upgrade. Move into the next room and take cover behind some nearby pipes. There are some Blue Suns pyros here along with rank-and-file troops. When they're gone, proceed across the catwalk to continue the hunt (see the "Escape the Refinery" section).

Save the Workers
If you've chosen to save the refinery, head down the stairs and to a locked door. Bypass the lock and continue through. In the next room you will have to use control panels throughout the room to switch off fuel lines, stopping the fires that block your path. The panel is near the obstacle so finding it shouldn't be hard. While you're in here, be sure to check for some salvageable credits. On the upper level, maneuver around the fire and grab some palladium before heading through the door. A research terminal in the control room has a Heavy Weapon Ammo upgrade. Activate the fire extinguishers and exit the room. Make your way across the catwalk and down a pile of crates to go after Vido (see the "Escape the Refinery" section).

Escape the Refinery
This section is mostly the same, regardless of which choice you made earlier.

On some pipes to the left is a crate of palladium. Just a little father along, on the floor, is the M-451 Firestorm, a heavy weapon/flamethrower. In the room on the right are a couple more Blue Suns mercs; if you like, try out your new weapon to make some fresh Kentucky Fried Turian. Once the coast is clear, search the room for salvageable credits and some power cells. Right next to the power cells is a weapon locker in case you'd rather not use your new heavy weapon. Head into the next room and take cover for a big firefight.

Vido will send a wave of mercs in from both sides of the room to start. There's a covered firing position near a large cylindrical tank that should allow you to move and provide a sizable field of fire. Once the first wave is down, Vido will trigger a ceiling-mounted fuel tank on the right side of the room. You can shoot this down on top of your enemies to finish them off quicker. After a few moments, the same will happen to the tank on the left; rinse and repeat. With the troops dead, Vido will send out his last line of defense, a YMIR mech. As always, focus on countering each of it's defensive layers (preferably while in cover) before finishing it off with firearms. When the mech is down, check the room for a med kit and two machines containing salvageable credits. Once you've got everything, head through the loading doors on the far side of the room.

If you chose to ignore the workers earlier, Zaeed will shoot Vido in the leg, then use a hot thermal clip to ignite a puddle of fuel, burning Vido alive. With that, you'll have Zaeed's allegiance. If you instead saved the workers, Vido will already be aboard his gunship when you arrive on the landing platform. While Zaeed's careless shooting will hit a passenger, Vido still gets away safely. In his anger Zaeed confronts you, but his spent thermal clip ignites a puddle of fuel and detonates the nearby tank. Zaeed will end up trapped under a girder, needing you to get him out alive. At this point, you'll have lost your opportunity to gain Zaeed's loyalty unless you can Charm him into realizing that he brought this all on himself. If you got his loyalty though, he'll get new clothes and a new power, Inferno Grenade.