Doomsday Heist Act 1 Finale (The Data Breaches): Full Walkthrough

Conquer The Data Breaches! Our full finale walkthrough guides you through the assault, defense, and securing your Act 1 payout, plus Elite Challenge tips.

This is the full walkthrough for The Data Breaches, the finale of GTA Online's Doomsday Heist Act 1. This guide will take you through each step of the intense assault on the enemy facility, the critical defense of the IAA assets, and also includes details on potential payouts and the elite challenge for this act.

Payout (normal): $975,000
Payout (hard): $1,218,750

The finale is quite easy if you are careful. For this mission make sure you have a full stock of snacks and armour. You will also need an Armoured Kuruma — it will help you a alot in the first half of the mission.

First, you and your friend hop into the Armoured Kuruma and go to the facility. Once you reach the facility, you will see a lot of guards — since you're inside the Kuruma though, you don't need to worry about getting shot. Take out all of the enemies and you will see a camera feed cut scene showing you and your friend entering the facility.

Killing the guards outside the facility while inside an Armoured Kuruma

Inside the Facility

Once you are inside the facility, you will need to take out lots of enemies before proceeding forward. So as soon as you're inside, quickly eliminate whatever guards are in front of you. After that, once you pass the metal detector, take cover by the wall to your left and take out the guards across the glass window. Keep clearing and moving forward. As you're moving forward always keep an eye out for the platforms outside the glass window, soldiers randomly spawn there and can rapid fire and instantly kill you. Always keep looking around.

Enemy across the glass window on the platform

Keep moving forward and then go through the doors to your left which will take you to the stairs, leading down. As you're going downstairs, some more enemies will spawn on the stairs, take them out and keep moving. When you reach the next level down, there will be a couple of interrogation rooms and a soldier in each room for you to kill. Be careful not to ignore them, as they can come out of these rooms and kill you as well. There's a double door at the end of the hallway and two soldiers will rush you from there as well. So keep an eye out for them also.

Soldiers coming through the double door at the end of the hallway

After clearing out this floor, keep going down. You will see a brown double door to the right, with a yellow marker for you to go to. Keep going downstairs while fighting the soldiers. You will reach the bottom floor at this point and should see an opening ahead of you. Do not go in there, just take cover by the wall and kill all the soldiers from this position.

Once you've cleared the bottom floor, you need to head back up to the interrogation room floor and go through the double doors where the two soldiers came out before. That room is actually a 'War Room'.

Enter the War Room

Once you reach the War Room, use one of the gun cameras to take control of the radio controlled missile turret. After gaining control of the turret, kill every soldier coming towards you. There will be a couple of helicopters as well. You will also see IAA Defense's "health" bar on the bottom right corner of your screen — you need to ensure the Defenses do not get low or else the mission will fail. Take them all out and eventually they will start trying to run away.

That is when your finale successfully ends, followed by a cut scene.