Headhunting DLC, Automatron Quest
This quest will be triggered or can be aquired when you complete A New Threat quest.
Related points of interest
Stages of "Headhunting" quest
1. Collect second Radar Beacon
Ada has detected a second Robobrain. I should head out to the location and retrieve its Radar Beacon.
Go to the location marked on your map and kill the robots there. Radar Beacon is inside Quantum Robobrain corpse.
2. Speak to Ada
I've retrieved a second Radar Beacon from a Robobrain. I should bring the device to Ada, and find out where the third and final Radar Beacon is located.
3. Proceed to Fort Hagen Satellite Array
Ada has identified the Fort Hagen Satellite Array as the location of the final Robobrain. I should proceed out there to retrieve its Radar Beacon so we can finally locate the Mechanist.
4. Enter Fort Hagen Hangar
The door to the Fort Hagen Hangar is locked, use the Rust Devil Entry Terminal to open it.
Terminal is at the end of the footbridge above.
6. Speak to Jezebel
The signal Ada found seems to be broadcasting from the head of a Robobrain connected to a strange machine. I should attempt to communicate with the head and see if it will relinquish its Radar Beacon.
7. Take Jezebel
The Robobrain head that calls itself "Jezebel" has agreed to help me find the Mechanist and access the Mechanist's facility if I take it from Fort Hagen Hangar and find it new body.
After taking Jezebel you will have to kill robot AHAB.
8. Exit the Fort Hagen Hangar
I've agreed to help the Robobrain head that calls itself "Jezebel" escape from Fort Hagen Hangar. In exchange, Jezebel has agreed to tell me how to access the Mechanist's facility and relinquish its Radar Beacon.
The way you came is locked, you need to find another way. Go this way.
On your way out you will find Fusion Core Generator, and terminal with a new holotape - Automatron.
You will also meet Ivey. When killed she drops Tesla T-60 armor parts and Tesla Rifle.
9. Speak to Ada
I've managed to escape from the Fort Hagen Satellite Array in one piece. I should now give Jezebel's head to Ada so she can remove the final Radar Beacon.
10. Build Jezebel a Body
In order to discover how to get into the Mechanist's Lair, I should use a robot workbench to build a body for Jezebel's head.
Go back to your Robot Workbench, use it to build a new automatron and then attach Jezebel's head to it.
11. Speak to Jezebel
Now that Jezebel has a body, and I've kept my promise, I should speak to her to find out how to get into the Mechanist's Lair.
12. Quest completed
Jezebel has informed me that I'll need to outfit a robot with a device called an "M-SAT" in order to gain entry to the Mechanist's Lair. She uploaded the plans for the modification to my Pip-Boy.
Next / new quest is Restoring Order (DLC, Automatron).