Activate it, then go about meeting up with Alpha Squad . On the way back to the mining facility you'll have to deal with more Helghast but if you take cover to the left and move on through the corrugated iron scenery you won't have to fight them face-to-face and can get a far superior angle of attack. Navigate above their position and rain death from above.
Follow the waypoint back to Suljeva Village and find out that, horror upon horrors, Alpha Squad have been taken by Colonel Radec and his properly unformed men. You are going to have to rescue them, so follow the waypoint and get ready to see what heroics will do for Garza's survival prospects.
Pick up a Light Machine Gun and use it while crouching to take out Helghast at a distance. You'll now know that the blue lightning is powered by a mineral unique to the Helghast home world - Petrucite.
In another dumb move on behalf of your enemy you will see that they store volatile Petrucite canisters all over the place and one shot is all that's needed to set the stuff off and cause massive damande to anyone nearby.
Avoid direct contact by taking pathways around enemies and shoot them from their side. Keep your head, be methodical and you will find yourself on the Petrucite mine train in no time.
MISSION SEVEN: THARIS REFINERY
Sev and Rico must take control of the Helghast train if they have any chance of finding their captured buddies alive and that means getting involved in a classic bit of first-person shooting that only being forced up the narrow confines of a train can provide.
For reasons unknown you will start the mission with only your pistol as weapon, but the first Helghast you kill will drop a Sub-Machinegun that has enough rounds left in it (should you kill its previous owner quickly enough) to kill another Helghast - this time one with a Shotgun. Move down the train and take the steps that lead to a higher level where you will find a weapons rack that has more SMG and Shotgun ammunition.
Take more stairs and you will enter a compartment overlooking a Helghast position. Look! They are standing right next to Petrucite canisters! Shoot the blue canisters for a speedy set of kills and move on to find another weapons rack, this time one that will provide you with an Assault Rifle.
Move down the train with your new rifle and use its decent killing range to take out some more infantry units and then quickly pick up a nearby rocket launcher and take out the tank. Take out the Helghast attacking with RPGs and other more basic grunts before entering the driver's coach where Rico will use his great diplomacy skills to persuade the driver to stop the train.
Rico and Sev split up, but not before Rico opens fire on some unsuspected Helghast and then has the audacity to complain that you've lost the benefit of surprise. Move toward the waypoint and note that there's a Helghast Symbol on the side of the train to your left. Shoot it, then enter the station to your right and follow the blue power cables. You'll fall through the floor and into a different section - the lower Refinery Complex.
LOWER REFINERY COMPLEX
Shoot the spider that should be harassing you and then blast the Petrucite power box in the next room to stop the electricity from blocking your path. Move onward and you will see enemy units visible through a door to your left. Blast them through the doorway before moving through it and dealing with any stragglers that are left using automatic fire and look to the left and shoot the blue power box.
You can now take the path that was obstructed and run up some stairs. There's nothing of note up here, but you will now have access to a lift that will take you down to do battle with yet another Heavy Weapon Trooper, but this time once that's armed with a gun that blasts electricity that can kill you quickly. This HWT is incredibly tough, but also incredibly stupid so run away from it and look above you where you will see containers being transported.