Fallout 4
84 Achievements
1,600
108-139h
Underground Undercover
Complete "Underground Undercover"
10
3.15%
How to unlock the Underground Undercover achievement in Fallout 4 - Definitive Guide
1. Road to Freedom
2. Tradecraft
3. Underground Undercover
For help on joining the Railroad see the guides for the achievement Tradecraft.
This achievement is a prerequsite for the achievement Rockets' Red Glare.
For how this achievement can be missed please click on the spoiler below.
More details here:
https://fallout.fandom.com/wiki/Underground_Undercover
This solution is for fixing the Warn Desdemona glitch:
After months of trying everything I could think of including a new playthrough, I figured it out.
When you do the mission Memory Interrupted not only must you NOT LET GLORY DIE, you have to GET HER OUT OF MALVERN STATION. Near the exit to the station Glory can get caught on a turnstile & never get out. I couldn't push her away, but I kept standing up against her back until she pushed through & exited the station.
To be on the safe side I escorted her all the way back to the hideout. She will then turn up at the appropriate times for those wanting to do the Railroad ending.
I really hope this helps anyone else who was stuck on getting this achievement.
MISSABLE!
Quest Giver: Desdemona
Location: Railroad HQ
This quest spans quite a bit of the Institute quest line as well. Do not feel as though you have gone too far in the Institute if this is still open in your quest log. You end up doing over half of the Institute quest line before this quest wraps up, keep it in mind.
MISSABLE! - Completing the quest for the Institute called "The End of the Line", will make The Railroad hostile and prevent you from completing their quests for good. ACCEPTING the quest for The Brotherhood of Steel called "Tactical Thinking" will also make The Railroad hostile! The game tells you this though before you do those actions.
Faction: The Railroad
Quest Giver: Desdemona
Location: Railroad HQ
This is a fairly long winded quest and does involve some waiting around in parts. The main thing is you need to continue working with the Institute for one of the quest steps. This step wants you to complete up to "Powering Up". Once you complete that quest, a Synth will come up to you and allow you to follow the reaming steps. Be warned though, because the Brotherhood of Steel will attack the Railroad and be hostile towards you. Once you have killed them all, the quest will be complete.