Tradecraft Tradecraft is a Railroad main quest and an achievement / trophy in " Fallout 4 " . Detailed walkthrough . The quest begins immediately after completing Road to Freedom . The conversation with Deacon will change depending on the answer to Desdemona ' s question , if the Sole Survivor would risk their life for a synth . Either way , Deacon has an angle for getting past the usual , year - long procedure of becoming a Railroad agent , suggesting a two - man mission to the Railroad ' s former hideout in Lexington . Meet him on the city ' s outskirts to continue the mission . Outside Lexington , Deacon provides more details on the job , as well as introduces the player character to a few railsigns , and gives the player character a countersign ( " Mine is in the shop " ) to use with Ricky Dalton , a tourist they ' re about to meet . They rendezvous with Ricky , who asks the Railroad ' s sign " Do you have a geiger counter ? " The player character can use the countersign or not , afterwards Ricky explains that the Slocum ' s Joe is crawling with Gen - 1 synths . Option 1 : Frontal assault . Proceed to the Slocum ' s Joe front entrance and begin a frontal assault . You will also need to circumvent or disarm all of the mines littering the front of the shop . Once inside , however , Deacon will give you the location of the hidden elevator only to realize it has been powered down , forcing you to use Option 2 , sneaking in through the escape tunnel . ( However , before update 1 . 4 it is still possible to enter this way by opening the elevator doors , jumping down the shaft , entering the elevator box via the hatch at its top , and opening the doors at the bottom . Careful of the mines in the hallway though . ) Option 2 : Escape tunnel . Go back to where the Sole Survivor met Deacon and head to the quest marker , a sewer tunnel covered by a thick drape of moss . Upon entering the tunnel , the player character is given a little more information about the Railroad and the target . Shortly after the talk , Deacon will unlock the terminal with a few passwords he remembers . Past the door , Deacon will point out a railsign signifying that there ' s a cache nearby . ( It ' s in the back of the tube directly behind the sign . ) Around here , Deacon will warn to just run if meeting a Courser ( provided the player character hasn ' t previously fought one in the Hunter / Hunted quest ) . Ahead , there will be an unlocked terminal , which one can use to turn off the spotlights and turrets . Below is a group of synths that need to be passed . Once past this group , one can turn on the defenses that will start firing immediately against the next group of synths . Shortly after that , one will find out that the Railroad was using an old Defense Intelligence Agency site as their HQ . The terminal next to the door leading out of this office area can turn off the tripwires in the next room . Before leaving , grab the fusion core in the room left of where the Sole Survivor first entered and a U . S . Covert Operations Manual on a desk in the room up the stairs . Once entering the last room before the marker , Deacon will open the vault and inspect a dead body . There are two hazmat suits and a bottlecap mine in the room before the vault , opposite a weapons workbench . After the inspection , he ' ll offer the " hand cannon " the dead man used and won ' t take no for an answer . In the vault , grab Carrington ' s prototype , the two Stealth Boys , the mini nuke and head towards the elevator . Before the player character leaves , to the right of the small set of stairs leading to the elevator is a locked door with an advanced lock where the player character can find another fusion core . Once back to the church , the Sole Survivor finds Deacon embellishing their exploits to Desdemona . The Sole Survivor has the option to tell the truth or pass an easy persuasion check to go along with the lie . Either way , she ' s impressed with their resourcefulness and extends an invitation to join the Railroad . Refusing leaves the offer open , but accepting leads to selecting a code name ( or letting Desdemona pick ' Wanderer ' after refusing a name twice ) and completion of the quest , with Deacon becoming available as a companion .