How to do 'Road to Freedom' quest?

I started the Road to Freedom quest but the marker on the map disappeared and I am not sure what to do at this point?

How do I progress with this quest?


As detailed on the Fallout Wikia page for this quest:

Quick walkthrough

  1. Follow the Freedom Trail.
  2. Continue following the Freedom Train.
  3. Search for The Railroad.
  4. Talk with Desdemona.

Detailed walkthrough

  1. Acquire the quest in Diamond City.
  2. Travel to Boston Common and speak to the Tour Bot
  3. Follow the red trail on the ground from location to location, looking at the markers as you go along until you reach the Old North Church.
  4. Inside the Old North Church, in the basement, there's another Freedom Trail marker with a ring that spins, turn it and press the button to spell the word RAILROAD.
  5. Once the door opens, go inside and speak to the people there, you can pass a difficult speech check to be told who they are first, or just tell them who you are. When asked how you found out about them you can pass a speech check to lie, but there's no immediate obvious results of that.
  6. At this point you're introduced to Deacon, a spy who has heard of you, he vouches for you and you then get to discuss why you are there.
  7. You are then asked if you would risk your life for a synth, either way the quest will complete and you will be offered work by Deacon, but if you say no then Desdemona, the leader of the Railroad, disapproves.
  8. Once Road to Freedom is complete Tradecraft starts immediately.

It turns out one needs to follow red brick line that starts at the robot. Note that for various parts of the path this line disappears under rubble and is painted on the ground with arrows and red lines.

Here's a video following the trail:

Once you've arrived at the Church at the end of the trail and followed the path through the basement level of the Church you will come to a dead end with a button and dial which isn't all that obvious, and a secret door: