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The recommended active skulls for this mission are Tough Luck, Catch, and Fog, but mostly Tough Luck. Tough Luck sacrifices the full potential of your grenade arsenal, and EMP/Headshot kills will be tougher to win, but in exchange for a reasonable multiplier. As for Fog, the battles in both Lake Beds could be a bit awkward, and you'll need to be extremely methodical during the final battle to hunt down Grunts and Jackals. With Catch, Factory A and the warehouse are more difficult, but Catch is an invigorating addition if you're not aiming for speed.
The mission starts as you ride on a Warthog and head towards a factory in the city of Voi. Exit the vehicle as soon as you can and open the door by pressing the button the side. First grab a Plasma Grenade from some dead Grunts around the area. You may want to grab a Troop Transport Warthog to use for splattering in the first few areas of the warehouse. Enter the factory and go up the stairs. Keep walking to the left until you reach a room. Enter it and pick up a Battle Rifle. Stay upstairs and go to the opposite end. There will be a few Grunts and Jackals downstairs. Use the Battle Rifle to wipe them out before letting the Warthog in. It may be tempting to just open the door and let the Warthog roll in, but its almost certain that it'll meet a short and miserable demise in the hands of a Grunt carrying a Plasma Grenade.
After clearing out the first group, more Grunts will emerge from the far right-hand corner of the room, which is obscured by crates and barrels. You can collect more Battle Rifle ammunition from beside a fallen Marine to the left of the closed gate.
You can simply open the next gate and follow the Warthog, but there's generally no cover at all if you do so. The recommended technique is pressing the button and them immediately running onto the walkway to your right. From this position, you can ambush Covenant troops with grenades and your Battle Rifle. The majority will be too distracted by your Warthog turret to worry much about you. There are two Type-32 Ghosts at the far end of the corridor. Any surviving enemy infantry may or may not use them against you. The sound of one accelerating or firing is a signal to get out the way immediately. Use Plasma Grenades against these if your ally on the turret is too slow to deal with the threat. Note that a charged Plasma Pistol shot and a hijack also works well. But disabling one and running out into the open to hijack gives the other Ghost a chance to either shoot or splatter you to death.
The Warthog will rarely survive this full head-on encounter, so the safest way to keep it intact is to head through the passageway and launch an initial solo attack with your Battle Rifle. Pick up a Plasma Pistol to duel wield with your Magnum to dispatch any aggressive Brutes. Then aim to thin their numbers by killing Grunts, Jackals and any adventurous Brutes. When only a few enemies remain at the end of the corridor, let your Warthog roll in and finish them off.
Aiming For Points?
If you want to keep the Warthog alive and get more points, try this method.
Follow the Walkthrough above until you reach the second gate. Open it and board the Warthog. Spaltter the Grunts and Jackals while avoiding the plasma grenades. Since the vehicle cannot be destroyed while you are alive, so just focus on ramming enemies and keeping yourself alive.
This method will get you more points, and also keep the Warthog alive for further use.
Lake Bed A
Open the gate, jump into the Warthog's driving seat, and cruise along the side of the dry lake bed, mowing down any Brutes and Grunts in your path. Stop at the start of the boardwalk leading to the little building. Exit the Warthog as your gunner lays waste to the Covenant on the roof. Make sure you clear this area quickly, a Phantom will deploy a Type-26 Wraith outside the far exit at this point., and the Ghosts circulating the lake bed will already be converging on your position.
In the Lake Bed, next to the ramp closest to the door you came through, there is a Warthog TT, which you can use if your other Warthog is badly damaged. It is flipped and the Ghosts will kill you and the Marines if you try to.
Remember to keep moving, or the Wraith will hit you.
Get on top of the small building, and collect the Sniper Rifle and the Missile Pod. Use your Sniper Rifle to dispatch the gunner of the ordinary Wraith (not the Anti-Air one, leave that alone for now). Deal with the reinforcements the Phantom sends down. The Missile Pod will enable you to destroy some (though probably not all) of the Ghosts below. They can be a big nuisance and so should be neutralized as soon as possible. Drop the Missile pod as you near the ordinary Wraith. Hijacking it successfully will make the rest of the battle a lot easier. It is better on the Phantom dropping the Wraith, as it cannot move or attack if the Phantom is destroyed.
The final part of the battle is a cat and mouse game against the remaining Ghosts, if there are any. If your Warthog crew is still alive, they'll engage any that come within range. This works well as a diversion. You have two reasonable choices. Either snipe the Grunt drivers from afar, or bombard them with the Wraith's main cannon.
With all the Ghosts out of commission, snipe the gunner of the Anti-Air Wraith, then grab yourself a Ghost. Drive over to the Wraith, approach it from behind and pummel it with melee attacks. Don't even bother trying to destroy it using your Ghost's plasma cannons, that will take an absolute eternity. Jump off and hop back into the Ghost. Two Banshees will fly in the attack you. A friendly Hornet will then engage and destroy them on your behalf. Although it is wise to boost into cover with the Type-32 Ghost before any of them open fire. If you are on the Wraith, blow the Banshees up to get more points for the achievement on this mission.
The door to the next area will now be open, a small force of Grunts and a Brute will exit the factory. Freely choose how to kill them, but watch out for the turret. They only appear on Heroic and Legendary. Then prepare yourself for the next encounter, because this Factory won't be as hospitable as the first one...
There will be several Grunts and Jackals in the room beyond the gate. Use the Ghost's plasma cannons to neutralize them. Attempting to splatter them could end in your vehicle being stuck by a Plasma Grenade. Jump out and grab the turret outside. The Brutes upstairs are in possession of Power Drains, so its unwise to engage them in a vehicle. And in a fight like this, being paralyzed is the last thing you'd want to happen.
The Chieftain generally won't come downstairs to attack you, but you can lure other Brutes to your location. Try lobbing grenades upstairs if you've got a good supply. Pick off any wandering Brutes with your Plasma Turret, but be careful to dodge the Chieftain's shots. This one also wields a Plasma Turret, so you'll have to be quick. Once the bodyguards are dead, switch to your Battle Rifle and wear the Chieftain down with several headshots. Be patient, as this process might take some time. Use any Sniper Rifle bullets if you still have some. Collect the Chieftain's turret and make your way to open the gate.
Enter the next room and point your turret at the skylights above. A swarm of Drones will smash through. Fire at them as they descend and go through the gate for cover once they return fire. Be advised that the majority of them carry Needlers. This is the best place to operate from. It is rare that a Drone will follow you through. Constantly keep darting out into the open and dispatching a few more before retreating into cover to let your shields replenish.
Grab a Rocket Launcher in place of your Sniper Rifle and stock up on Battle Rifle ammunition at the weapons cabinet prior to departing. The Rocket Launcher may seem unnecessary, but it'll actually be useful for a battle that occurs much later on. The best combo is the Sniper Rifle and Rocket Launcher, because you will need to snipe some Brutes down later on. More ammo also comes for the Sniper Rifle at Lakebed B.
RALLY POINT ALPHA
Lake Bed B
It is possible to destroy all the vehicles and the Anti-Air Wraith whilst driving a Mongoose, but on Legendary, this is suicidal. the Ghosts and Phantoms will mow you down as soon as you drive out into the open.
Although there is a different, easier way to win this battle. As soon as you hit the bottom of the lake, drive directly to the two fixed Missile Pod turrets to the left of the battlefield. There is a small group of Grunts and a Brute at this position, quickly run them down, or slow down and let your Marine riding pillion blast them. Drive up the ramp and park your Mongoose safely. Your passenger should protect you from incoming vehicles.
Take control of a Missile Pod and leave it on its mounting for infinite ammo. Aim to smash absolutely everything within sight. That includes Ghosts, Wraiths and Phantoms. Duck into cover when enemy vehicles threaten you, or temporarily run to the other turret. Should your turret be tipped over, you can simply use the other one. If both have been knocked down, you'll just have to use the remaining sixteen missiles wisely. The Ghosts, Choppers and Banshees are your top priority, the sooner you wipe these out, or at least thin their numbers, the better chance your allies on Mongooses have of destroying the Anti-Air Wraiths and surviving this opening part of the battle. If the other vehicles are under allied control, incoming fire from the Phantoms is the only danger here, so you should aim to blow these from the skies. The only good reason you should leave this position is if your allies have difficulty destroying one of the Anti-Air Wraiths. Return to the Missile Pod promptly after that Wraith is destroyed.
An enormous Scarab tank will pass overhead and onto the lake bed. With the Missile Pod turret, open fire on its deck, turrets and leg joints, this would sufficiently weaken both the vehicle and the crew before it manages to turn and attack you. If a few Mongooses survived the earlier confrontation, the Scarab won't fire at your position for a while, giving you more time to take it down. If it does start firing at you, get into cover immediately. There's a high chance the frontal beam will knock the turret over. Remember that there is another turret just a few steps away.
There are two recommended ways of destroying the Scarab. One way is to use the elevator to travel up when the Scarab moves underneath one of the two cranes. If you desire to snipe first, go to the one near the door, for there is a dead Marine with a Sniper Rifle over there. Run over and jump onto its deck. From there, it's a short journey to the engine core at the rear of the vehicle. Be careful however, marines on the missile turrets can accidentally hit while you are on or near the Scarab, which is a one-hit kill on Legendary. Also, the height is high, and a mistake will be fatal. You can grab one of the Plasma Turrets to dispatch any surviving infantry, and then finish off the walking tank with ease. The missiles that you used to bombard the deck should have left only a small handful of enemies left. Otherwise, use the Sniper Rifle at the top of the crane nearest the exit to eliminate the most dangerous targets from afar before launching a direct assault. The other way is to not leave the Missile Pod turret. When its rear is faced towards you, fire at the engine core simultaneously. Some of the missiles are bound to hit it and end the Scarab with a bang. It makes it safe because the Scarab will not go to the Missile Pods, and you don't have to knock it down.
Once the second Lake bed is cleared of all enemies, Thel 'Vadam will arrive in a Pelican. Enter the room to the left of the Missile Pods and pass through them. Ensure you have a full supply of Battle Rifle ammunition before you head into the warehouse area. Head up the crane elevator and grab the sniper rifle, it can come in handy later. Carry a missile pod with you, but don't drop it until the Cortana moment. Otherwise, it will disappear. The missile pod can be used to destroy the Hunters that appear later.
The first large room contains a handful of Brutes. This battle isn't particularly tough. If you save the Marine of the upper walkway, the next fire fight, which involves a larger force of Brutes, relatively easy, as he will man the fixed turret. Thel 'Vadam and the Marines should hold off the other while you do this.
Once the advance party has been dealt with, run over to and head through the empty shipping container to the far left. Shoot the Brute on the other side. This will enable you to flank the larger Brute pack to the left. If you saved the Marine earlier, the turret fire can wipe out the Brutes in seconds. If not, or should the Brutes deploy Bubble Shields, you'll need to be quite patient. Watch out for Spike Grenades and try to not waste unnecessary Battle Rifle ammunition, you'll need it later. If your Machine Gun Turret is running low on ammo, grab the one on the walkway prior to moving on.
As you round the corner, you'll encounter two human workers battling against another pack of Brutes. Run around the right to flank them. If you operate from behind the crate, you can dispatch each Brute in turn while they are distracted by your allies.
If you have been patiently saving the Rocket Launcher since acquiring it in the second factory, your diligence pays off. Dash over to the exit and blast them with rockets as soon as they enter the warehouse. It should take no more than three or four shots to kill both (you can have more troops if you rush ahead and destroy the fusion coils).
When the Warehouse gate opens, a bunch of workers are running away from two Hunters. One of the Hunters hits some Fusion Coil, killing all of them. On Heroic, a Rocket Launcher blast will kill them instantly.
The outside of the warehouse is dominated with Covenant forces. A Brute Chieftain flanked by two Brute bodyguards armed with Carbines waits patiently for your arrival, along with a group of Grunts. There are two options here. The first option is to take out your Battle Rifle immediately and kill the Grunts first so that you won't be bombarded by grenades with the Catch Skull on. At this point, the Chieftain and his guard will usually withdraw. Aim to take down at least one bodyguard while his back is turned towards you as you cautiously move outside. Take out the second bodyguard straight away, then turn your attention on the next wave of Grunts and Jackals before Brute reinforcements arrive. Make use of every opportunity you have at shooting the Chieftain. If you're lucky, you can even kill him before he charges, and pick up his Invincibility unit. Note that there is a Battle Rifle just outside the warehouse if you're low on ammunition.
The second option is to climb the indoor stairs beside the warehouse exit and go through the door at the top. in the second office, you'll find a Sniper Rifle. Smash the window with a melee attack, then snipe the Brutes, especially the Chieftain, from this position. If you're lucky, you might even kill the Chieftain straight away with a few accurate shots to the head. When the area is clear of all Brutes, you can exit by moving to the left of the window. Then use your Battle Rifle to wipe out the remaining Grunts. The Chieftain does not use the office rooms and does not charge there, though his bodyguards will attack you.
It is easy to think that the Rocket Launcher would make easy work of the Chieftain, but sadly, that is rarely correct. Chieftains at full strength can survive the first rocket, and more often than not, he'll activate his Invincibility unit straight away. This one carries a Gravity Hammer, which is the reason he possesses the Invincibility, so dodging him is a matter of running, jumping, dodging and panicking all over the place. You can retreat to the warehouse and let the Chieftain kill your allies as a distraction, but this is a shameful act of cowardice and denies you support during the final battle.
This battlefield is littered with useful weapons, including Carbines, Needlers and Plasma Pistols. The final Brutes aren't too difficult to finish off. Before you press forward, pick up as much Carbine ammo as you can, and, if you didn't do it before, pick up the Sniper Rifle in the office.
The Anti-Air Gun
As you advance to the next battle, there will be a missile launcher to your left. In front of it is more Sniper Rifle ammo. Collect it and aim at the opposing attack force. You can actually end the battle here by blowing up the exhaust vent on the AA Gun with your sniper rifle, but it will take a fair amount of ammo. If you can't then run up the hill. A Chieftain armed with a Fuel Rod Gun will briefly move into the line of fire before retreating, usually after firing a few blasts at your position. Attempt to land several shots on him. Blowing off his helmet is good enough, killing him straight away is a scarce achievement. You can only fire four shots at him before he ducks back into cover, it takes three to blow his helmet off, and one to penetrate his bare head. Weakening him at least is a massive starting advantage.
Note: If you're not playing for points, give any surviving Marine/Worker what remains of your rocket launcher, as they have unlimited ammo.
Pull out your Carbine and dispatch the Grunts and Jackals that run down the slope. Watch out for Grunts on the Plasma Turrets. When you're done, replace your Carbine with a Battle Rifle near where the Sniper Rifle was, only if necessary though. Cautiously make your way up the slope and top at the large rock to your right. Take out any Jackals and Grunts in the vicinity. When all is visually clear, inch forward until you can see the Chieftain, if you didn't manage to kill him earlier. You can also see other Brutes a few meters away. Downing the Chieftain and dodging his incoming Fuel Rod Gun blasts are your top priorities. Marines and workers should be protecting you from Grunts and Jackals, but grenades can be a nuisance, especially from behind. It's relatively easy for an enemy from behind to plant a Plasma Grenade on you and send you back to the previous checkpoint.
Once you've dealt with the Brutes, you should be concerned about mopping up any stray infantry before completing your last objective. Overconfidence is lethal, especially on Legendary, so explore the area slowly and methodically, always proceeding with caution. It's usually a long way back to the previous checkpoint. Use Plasma and Spike Grenades and/or the Fuel Rod Gun dropped by the Chieftain to destroy the exhaust vent at the bottom of the Anti-Air Gun. It opens up after firing each shot.
Doing this will destroy the last Anti-Air armament the Covenant has deployed. Admiral Hood's ships can now advance on the Forerunner artifact with ease, and you can enjoy the scenery.
Once you've reached the machine gun, use it to kill the Grunts and Jackals in your path. Quickly shoot the Chieftain. If you can lower his shields before he escapes, you're golden, because he will be more defensive during your attempt to destroy the AA Gun. Shot his bodyguards too, and hopefully, you can kill them, to avoid Spike Grenades attack on you.
When you've cleared the whole open area between the machine gun and the AA Gun, use your Sniper Rifle or Carbine to finish off the Brutes. After that, rip off the machine gun. Sprint at your fastest speed to the Plasma Turret. Be careful, you don't want to be sen by the Brutes and Grunts left. Arbiter will charged at his enemies, and keeping them busy. Turn right. You will see a narrow path leading to the back of the AA Gun. Keep walking stealthily until you reach to the site where you can clearly see the vent opening. Wait for the next shot.
After the vent opens, quickly shoot the vent with your machine gun. Dodge incoming Plasma Grenades and keep shooting. You probably can't finished the gun with the machine gun, so shoot it with your Sniper. Once the vent's core changes to red, shoot with your secondary weapon. Soon, you'll finish the final battle of The Storm with ease.
This way to complete the level is easier, and also safer. You can always complete the level without really challenging the Chieftain and other enemies. However, the path is narrow and dodging grenades requires fast reaction.
New Enemies: Hunter
New Vehicles: Scarab, Ghost, Anti-Air Wraith, Mongoose
New Items: Invincibility, unless gotten before in Sierra 117
New Weapons: Missile Pod, Rocket Launcher
Generally, you'd start the Floodgate mission with the same weapons that you used when destroying the Anti-Air Gun. It is instructed to finish with a Battle Rifle and a Sniper Rifle. If you want to do the Floodgate mission directly after this mission, consider trading the Sniper Rifle for something else before finishing the mission. Apart from the Fuel Rod Gun, there's some nearby Needlers to the southeast of the Anti-Air Gun. Consider taking this in place of the Sniper Rifle. There's a Plasma Pistol near that Needler, but it won't be of much help for most of that mission. There are a couple of Shotguns on a dispenser to your right in the first warehouse battle as you advance. That is a key weapon whilst combating the Flood. The Shotgun is also the recommended main weapon in the next level, but a Battle Rifle will kill them faster depending on your accuracy.
Using Points and checking the Carnage report will be:
? Infantry, ? Specialist, ? Leader, and 2 Heros (hunters)
? Light, ? Medium, ? Large, 1 Giant (scarab)
Askar Achievement Milestone: 15,000 points
Recommended Multiplier: 4+ (Tough Luck (1.5) + Catch (1.5) + Fog (1.5))
0-15 min - 3×
15-20 min - 2.5×
20-25 min - 2×
25-30 min - 1.5×