Act III: The Doomsday Scenario Ending Walkthrough – GTA Online Doomsday Heist

GTA Online Weekly Update: September 12-18

Act III: The Doomsday Scenario GTA Online Doomsday Heist has 6 Preps and 5 setups to progress to the finale. After the cut scene, you will see the Act 3 begins on the planning screen. After San Andreas defense systems have been hijacked, your job beings to save agents and stop the build-up of weaponry to save the world from destruction.

GTA Online Act 3 Walkthrough

Doomsday Heist Ending Walkthrough Act III

  • Setup Cost: $120,000
  • Payout Pool: $1,200,000
  • Payout Pool (Hard): $1,500,000

Prep 1: Marked Cash

  • Objective: Steal a duffel bag of marked bills from a dead drop being watched by the FIB.

As the mission starts you get instructions to steal a bag of money in order to save Agent 14.This money will be use to save the agent. So get to the marked location, and there you have to retrieve a duffle-bag. This bag is filled with money. Once you reach near the bag, you will see it was sting operation, escape the police and bring the money to facility.

Prep 2: Recon

  • Objective: Go to the shipyard to get some photos.

This one is a simple mission where you will have to visit the target location and click photos of around 10 spots in the area. This is the place where a deal for Agent 14 is going to take place. So there won’t be much fighting stuff here, just reach the place and take the pictures. Follow the screen instructions to take photos of the place.

Setup 1: Rescue Agent 14

  • Objective: Head to the shipyard, and attempt to purchase Agent 14 from Merry weather Security.

Doomsday Heist Act 3 Jaggernaut

This is a bit tough mission, you will have to take a bulletproof car here. You have to visit a shipyard to rescue the agent. There will be many guards in the area, so you have to keep patience here. Try to play slow and kill the guards slowly, don’t engage into a ambush. As you reach the place you will have to rescue the agent. After killing the guards you will have to deal with the juggernauts sent by AI Avon. These juggernaut will be invisible and they will attack with mini-guns. You can track them down using thermal goggles. Destroy them. This will be a bit tough fight, as you will be using the goggle to track them down. Take covers from Juggernauts attack, they will spread up fire, that can eat up your health really fast. Let them shoot first and then attack, next you have to fight the goons. Once done take the agent to the extraction point. You will have to fight your way out, towards the extraction point. You have to keep fighting the goons and a few more juggernauts in your path, once done, you will get 2 Akulas helicopter nearby. Finally take the agent to the drop off point.

Prep 3: Chernobog

  • Objective: Steal a Chernobog ballistic missile launcher from Merry weather security.

Doomsday Heist Act 3 Chernobog

In this mission you have to retrieve a mobile missile launcher. So go to the marked location on the map, and fight with the guards in the location. Once you are done killing the guards you have to get in Chernobog. It is a two-seater missile launcher, but the missiles are disabled. So take it and drive it to the facility. The vehicle is slow but it is strong, just keep it driving ignoring the one who are chasing you. As you deliver the vehicle to the facility the mission is over.

Setup 2: Escort ULP

  • Objective: Use the Chernobog to escort and protect Agent ULP as he makes his escape from the captors.

In this mission you have to use the Chernobog to escort Agent ULP. Once you get the location on the map reach the place, it will be some construction yard. There you have to fight with some soldiers, clear the area first. If you have a sniper you can spot them from distance. Split into two team, let one team go near and let the other stay back to defend from backside. To stay on the safe side, one of your team member can stay in the car and drive through the area, you will see the soldiers will come out. Kill the tea first and then take the Chernobog. Your team can assist you in the path to deliver the vehicle to the landing site. Once you reach the spot wait for Agent ULP. Once he is in the vehicle drive it to the next location. Others can protect the agent by destroying the chasers. There will be lot of helicopters spawning at this point. So target them. Once done follow the agent and the mission is over.

Prep 4: Flight Path

  • Objective: Eliminate an arms dealers to recover information on the Barrage ATV being flown into Los Santos.

Now this one is a pretty short mission, you have to go to the target on the map and eliminate it. All you have to do is reach the place, quietly follow the target, kill it and then take his briefcase. Take it to the facility and the Prep is over. Other team mates will assist you in escaping the cops.

Setup 3: Barrage

  • Objective: Intercept an arms dealer’s air convoy and take down a heavy-lift chopper to recover the Barrage ATV.

Doomsday Heist Act 3 Barrage ATV

In this mission you will have to steal the Barrage ATV from Avon. You have to reach the observatory and wait for the convoy. This is the ambush point where you will have to wait for a while. Look up and you will spot a few helicopters. You have to destroy the cargobob who is carrying the barrage. After dropping it, go to the barrage. Take the vehicle, and escape the place. Dive to the next position, one of your team member can use the ATV’s gun to shoot down chasing enemies. Once you reach the next location, you will have to fight with more enemies. There is a plane ahead, kill all the guards around. once you are done clearing the area you have to take the ATV to the drop off point. There will be few Avon people ahead blocking your path, you have to keep driving. They will also chase you, so shoot them.

Prep 5: Test Site Intel

  • Objective: Retrieve the test site location of the Khanjali tank from the house of one Avon’s employees.

This is more like a stealth mission, you have to reach a house which is guarded by many guards. The location will be random here. So go the house, and kill the guards first. Then there will be a scientist inside you have to kill him also and get access to the lock box in the house. Open it and you will get an Intel. Take the intel to the facility and the mission is over.

Setup 4: Khanjali

  • Objective: Destroy a supply of the enemy’s weapons at a scrap yard in the Grand Senora Desert and steal the Khanjali.

Doomsday Heist Act 3 Khanjali Tank

This one is a simple mission, you have to reach an aircraft scrap yard and fight with Avon people here to destroy the research in the ware house and then gets the tank. Go slowly ahead and first destroy the equipment. You will have to kill the enemies. Move slowly, one by one, there are ample of enemies in this part. Once done you have to steal the Khanjali tank. All four members of the team can ride in the tank, take it to the drop off point. A few choppers will chase you, you can use the tank weapons to tackle them.

Prep 6: Onboard Computer

  • Objective: Shoot down a prototype Hydra and recover the enemy’s broadcast signal from the crash site.

After completing all the prep and setups above you will be able to unlock this one. According to the objective, you have to damage the Avon’s jet. Once you damage it, you have to follow the jet’s crash location and then recover a module from the cockpit. Just get it and return to the facility.

Setup 5: Air Defenses

  • Objective: Use a Volatol jet to destroy multiple SAM turrets around Mount Chillad.

Doomsday Heist Act 3 Volatol

Once the setup starts you will have to reach a airfield. Go there and take the Volatol to Mount Chiliad. Once you reach you have to destroy Sam Torrents. You can see all the marked turrets on the map. You have to fly through towards them and destroy them one by one. There will be approx 12 turrets you have to destroy. Once you are done, destroying them by dropping bombs you have to take the plane back to the drop off point. There will be a cut scene.


Doomsday Heist Act 3 Finale

Once you complete all the preps, and setup above you will be able to get to the finale. Go to Facility planning screen and setup the cut for your team mates. This is the last part of GTA 5 Dooms Day Heist. You have to reach Grapeseed first. Once you reach the location you have a choice to pick between Khanjali Tank or the Barrage. After picking one vehicle, the other will be sold and the amount of that sold vehicle will be added to the payout. According to Lester if you want to make more money you have to take Barrage, but the benefit of Khanjali tank is that it is nicely armored. So pick one as per your need and then move to a tunnel entrance. As you enter the tunnel there will be a cut scene, that shows a open door. Drive into the tunnel, and you have to fight with enemies here. You have to reach to the end of tunnel.

Once you reach at the end of tunnel, you will have to destroy more Avon’s enemies. Once you are out of the vehicle you have to deal with the Juggernauts. To destroy them fast use explosives, once they are gone you will be on foot, you have to keep progressing in the tunnel and keep shooting enemies blocking your way. You have to destroy the supplies, you will find the boxes in the rooms in tunnel, throw bombs on them to destroy it fast. Try to go slow through the hallway, don’t rush in. Try to take cover and moves. This will be a long mission so you have to take your time, go slowly and take covers around. You have to go to the Control Center. If you die you will be spawn back from the last place where you dropped your vehicle. Move slowly and let one of your team player take the lead. Go slowly by taking cover behind the debris around, it is easy to spot the foot soldiers. Watch for the Juggernauts also they will respawn in between. Once you reach the Control Center there will be a cut scene.

Doomsday Heist Act 3 Beam Puzzle

Once the control door opens up, there will be lot of soldiers ahead. You have to go slow, take your time and go. Look around properly inside this base you will see a lot of soldiers are around. You have to reach on the second floor and then towards the server. This will start a mini-game where you have to aim beam properly to complete the circuit. Check the image above, you just have to rotate the beam and avoid the firewall. There will be total 4 Servers you have to hack. Set one of your team member to hack the server and let others defend him. In this way you can side by side complete the server objective.

Doomsday Heist Act 3 Orbital Cannon

After you finishing with the puzzles you have to kill all the goons in the area. Kill them and go to the top floor. Then take the Orbital Cannon to destroy the mobile cloud servers. Just go near the console and you will be able to see the view, you have to destroy around 4 mobile cloud servers. Move the cannon slowly towards the target and destroy it. Just follow the target green arrow. Once you are done head to the Lab exit. As you cross the lab, you will see more goons ahead. You have to kill them and reach Silo. Go slow here, keep moving behind each other, so that in case you are attacked, one can defend you from backside. Once you reach near Avon Hertz, you will see a cut scene after which you have to use the Jetpack and follow him. This one is the final part you have to play, there will be helicopters first you have to destroy and then target Avon. Once done get to the Observatory.

Once all your teammates are down on the Observatory, you had completed Doomsday Heist. There will be a cut scene in the end.