This page is a walkthrough for The Doomsday Heist Finale Mission for Act 1. It’ll navigate you through the necessary steps to successfully infiltrating the Facility.
Prevent the IAA Servers from being hacked
Go through the IAA Base / Go to the War Room
Before you begin the mission, you’ll need to divide the Heist Payout between the crew. However, you’ll want to give yourself a fair bit more as the crew will get cash from the Setups whereas you don’t. Once you’re outside of your Facility, take your car over to the IAA Facility which is marked on your map.
Upon arrival, take out a Combat MG and use the surroundings as cover whilst taking down the enemies, then go down to the lower floor and clear out the remaining enemies. After the base has been cleared of enemies, go back up one floor and enter the war room. Finally, take control of the gun camera and clear out all the incoming enemies to bring Act 1 of the Doomsday Heist to a close.