During Year 4, after exiting the train station, walk down one flight of stairs and head right. You will find Glottis and some mechanics.
I suggest making a save here, as you need to speak to the mechanics before speaking to Glottis for the achievement, and if you don't position yourself correctly, you may accidentally talk to Glottis instead of the mechanics as they are quite close to each other.
Exhausting the mechanics conversation options will unlock the achievement.