Fallout Wiki
Fallout Wiki

It's commonly referred to as the "Molecular Relay." I don't understand all the science behind it, but it works. De-materializes you in one place, re-materializes you in another. I'm sure it sounds crazy, but it's a reality.Brian Virgil

The Molecular Level is a main story quest and achievement/trophy in Fallout 4.

Quick walkthrough

Main quest: The Molecular Level
Have the Courser chip analyzed.
Find the Railroad.
Return to Virgil.
Get help to build the Signal Interceptor.
Talk to the Brotherhood.
Talk to the Minutemen.
Talk to the Railroad.
Talk to Proctor Ingram.
Talk to Sturges.
Talk to Tinker Tom.
Build the Reflector Platform.
Build the Reflector Platform.
Build the Reflector Platform.
Complete the Signal Interceptor.
Complete the Signal Interceptor.
Complete the Signal Interceptor.
Optional: Talk to PAM about Mercer station.
Talk to Proctor Ingram.
Talk to Sturges.
Talk to Tinker Tom.
Use the Signal Interceptor.
Reward: 400+ XP.
Leads to: Institutionalized
From Within
Inside Job
Outside the Wire
Underground Undercover

Detailed walkthrough

At the end of The Glowing Sea, Virgil reveals that the Institute uses teleportation, and that this could be intercepted using information from a courser chip to construct a device, the signal interceptor. Before the Sole Survivor can utilize the newly acquired courser chip, it needs to be analyzed by someone familiar with the Institute's technology. The only person capable of doing this is Tinker Tom of the Railroad. If the Railroad has yet to be encountered, Dr. Amari will advise the player to follow the Freedom Trail to find the hidden Railroad HQ.

Once at Railroad HQ, speak to Desdemona and agree to her terms. Give the courser chip to Tinker Tom, who cracks the encryption and provides the code for the chip. If Tinker Tom is dead, there is a file on his terminal that automatically decrypts the data.

Return to Virgil. He offers the plans for the signal interceptor but now reminds the Sole Survivor of the favor that they promised him in their previous agreement: if the teleporter works, they must retrieve a serum from Virgil's old laboratory inside the Institute to cure his FEV affliction and make him human again. Accept his terms and receive the plans. However, the signal interceptor is no simple machine: expert help and a lot of resources are needed to construct it.

At this point, the Sole Survivor needs to make a choice to enlist the help of one of the three major factions (the Minutemen, the Brotherhood of Steel, or the Railroad). Speak to either Proctor Ingram (BoS), Sturges (Minutemen), or Tinker Tom (Railroad) and arrange for the construction of the teleporter. The chosen expert then travels to the building site and explains the requirements and necessary materials for each of the four components: the reflector platform, beam emitter, control console and relay dish.

The player can build the signal interceptor in the majority of allied settlements, including Boston Airport if they are allied to the Brotherhood. Note that both Home Plate and settlements from add-ons are excluded. Even though the Railroad suggests building it at Mercer Safehouse, one is not required to do so.

Constructing the signal interceptor

Build the stabilized reflector platform first in the target settlement, then speak to either Ingram, Sturges or Tom. Either of them gives the Sole Survivor the second list of resources required to complete the signal interceptor and will travel to (or spawn at) the settlement where it is built.

If building with the Brotherhood's help, Elder Maxson's permission is required before activating the signal interceptor. He moves from Boston Airport to the chosen settlement and might camp at allied settlements for the night along the way (he will be tagged on the Pip-Boy for his entire journey).

Requirements for the teleporter:

  • Enough flat surface area without any obstructions (the emitter needs to be built upon the platform, the combined structure - including a fusion generator to power it - can be squeezed in a 2x2x3 space).
  • Enough "size" allotment remaining at the settlement (the teleporter is quite large).
  • It requires 27 power.
  • The components have to be linked together with power cables on the same network.
  • For additional details regarding the construction of the signal interceptor, see its page.
Control console Molecular beam emitter Reflector platform Relay dish
  • Biometric scanner: 1
  • Copper: 3
  • Rubber: 2
  • Steel: 5
  • Circuitry: 3
  • Copper: 5
  • Military-grade circuit board: 1
  • Rubber: 2
  • Steel: 10
  • Aluminum: 10
  • Circuitry: 3
  • Steel: 5
  • Cloth: 6
  • Copper: 3
  • Gold: 3
  • Steel: 3

In order to craft all the items at once (not including the required power sources) the total quantity of each component is as follows:

When everything is built, linked together and supplied with enough power, the teleporter is ready for use. Talk to the expert and get ready for the voyage. The expert (of the assisting ally faction) instructs the Sole Survivor to stand on the platform, they are given a faction-dependent holotape, and then the teleportation process will commence.

Quest stages

Quest stages
StageStatusDescriptionLog Entry
10 Talk to Doctor Amari/The Railroad about the chipI have the Courser Chip, but I don't know how to decode it. Doctor Amari knows a lot about Synth technology. I should ask her for help. OR
I have the Courser Chip, but I don't know how to decode it. The Railroad knows a lot about Synth technology. I should ask them for help.
20 Find the RailroadI have to find the Railroad. I was told to "Follow the Freedom Trail." The best place to start looking is the Boston Common.
30 Talk to DesdemonaThe Railroad might be the only people who can help me decode the Courser Chip. I need to take it to them.
60 Tinker Tom decodes the chip
65 Search the Railroad HQThe Railroad might be the only people with a way to decode the Courser Chip, but we're enemies. Maybe there's something in their headquarters I can use.
100 Talk to VirgilI have all the information I need from the Courser Chip. Now to go back to Virgil and figure out the next step in breaking into the Institute.
200 Get help to build the Signal Interceptor
(Optional) Talk to the Brotherhood
(Optional) Talk to the Minutemen
(Optional) Talk to the Railroad
The Signal Interceptor should get me inside the Institute, but I'll need help building it.
300 Build the Signal Interceptor
400 Signal Interceptor completed
500 Step on the Platform
600 Obtain holotape
700 Signal Interceptor activates
1000 Signal Interceptor teleports the Sole Survivor into the Institute
1200Quest finishedCompletedThe Signal Interceptor worked. I'm inside the Institute. Now to find Shaun.


  • When it comes time to decode the courser chip, if the Sole Survivor has already eliminated the Railroad, they will need to search the Railroad HQ for a way to decrypt the chip and to get inside the Institute. To complete this objective, use Tinker Tom's terminal which teaches the Sole Survivor how to decrypt the chip.
  • Building the components at a different settlement than suggested may cause the quest giving NPC to travel, teleport or spawn there.
  • Both the Minutemen and the Railroad builds of the signal interceptor will cause the beam emitter to have one of its pipes burst in the middle of the launch. While this will have no effect on the result, the Brotherhood of Steel build won't have that issue and everything will go smoothly.
  • If one is not allied with the Railroad before visiting the Institute, and leaves there on friendly terms, the Railroad will no longer trust the Sole Survivor and will not let them join their faction. Along with story considerations, this may mean that one will never be able to build ballistic weave for the clothing.
  • In order to build the interceptor with the Brotherhood of Steel, one must complete several of their quests up to Show No Mercy, finishing the tasks for Elder Maxson. Then one is able to speak to Proctor Ingram to offer help.
  • In order to build the interceptor with the Minutemen, Preston Garvey will ask that the Sole Survivor first check with Sturges and complete Sanctuary when The First Step starts.
    • However, if Nuka-World is installed and the Sole Survivor becomes the overboss of Nuka-World prior to completing When Freedom Calls, then Preston Garvey will no longer work for the Sole Survivor and build the interceptor with them and in order to work with them more, they must wipe out the Nuka-World Raiders first, giving an opportunity to start Open Season, the quest that involves the destruction of the Nuka-World Raiders and freeing Nuka-Town's traders from slavery.
  • In order to build the interceptor with the Railroad, Desdemona will ask the player to complete Tradecraft and join the organization. She will discuss the interceptor once Road to Freedom is completed, but will not agree to help with its construction until Tradecraft has been completed. It is not possible to interact with Tinker Tom either until Tradecraft is complete.
  • If building the interceptor with the help of the Railroad, all the items required to construct the components (apart from the two specified items biometric scanner and military-grade circuit board) will already be deposited in the Mercer Safehouse workshop. Tinker Tom mentions that he will sort runners to get the components there ready. This happens twice, once for the reflector platform stage, and then again for the signal interceptor stage. It includes sufficient materials to build six medium generators, enough to power the device.
  • If building it with the help of the Railroad one may need to allow sufficient time for both Tinker Tom and Desdemona to get to the location of the Mercer Safehouse once the reflector platform is built and the quest log progresses. The map may show Desdemona's current location which keeps moving as she walks to the site if they have not reached it by the time one gets there. Waiting or sleeping for several hours should allow them to reach it and take up their positions close to the teleporter.
  • When stepping on to the platform, a holotape will be given. The Minutemen or Brotherhood will give the network scanner holotape. For the Railroad Desdemona will give the encrypted message holotape which will in this case also include the network scanner function.
  • If the player has already asked a faction to help in building the signal interceptor, it is possible to reset this quest branch point, provided that construction has not yet begun, or if the player is currently able to trade with the current faction's technical expert, and then kills them or turns them permanently hostile.
    • For example, the player is allied with the Railroad, then returns to Tinker Tom and trades with him to buy back the interceptor plans for no cost. After this, they kill Tinker Tom, which will turn the Railroad hostile. However, this allows the Sole Survivor to ask the other factions (Brotherhood of Steel or the Minutemen) for help with building the transporter.
  • Despite being marked as optional in the quest stage log, both the biometric scanner and military-grade circuit board are in fact required in order to construct their respective teleporter parts and progress the quest. The sensor module is not required for any of them currently. If one already has any of these in the selected settlement workshop (or carried at the time) then they will not be included in the quest stage log details.
  • In the Fallout 4 Vault Dweller's Survival Guide, the quest has a fourth option called "Misanthropic Moxie," that is, to build the teleporter alone at any desired settlement without the aid of any faction. However, this option is not available in the game. The publisher of the guide, Prima Games, has acknowledged the mistake.[clarification needed]
  • Sometimes, if the player has not already joined the Railroad, Desdemona cannot be interacted with. To correct this, simply head into the HQ itself and wait. Desdemona should follow. Talk to her, then return to the initial meeting point (and talk to her again) to complete joining the Railroad.


  • PCPC Playstation 4Playstation 4 Xbox OneXbox One If the Commonwealth Minutemen faction was chosen to assist, upon returning from the Institute, it will no longer be possible to assign a task to Sturges, nor relocate him, via the workshop menu. He will no longer require, or use a bed, nor will he count towards the population of Sanctuary Hills. It is still possible to trade items with him, however. [verified]
    • To fix this glitch, scrap every part of the burnt signal interceptor.
  • PCPC Playstation 4Playstation 4 Xbox OneXbox One Despite the inclusion of a sensor module on the signal interceptor - items needed list, one is not actually required to build any part of the teleporter. [verified]
  • PCPC If assisting the Railroad and the player character chose to create the teleporter at Jamaica Plain when talking to Desdemona about "Patriot," if she is too far away from Tinker Tom it will cancel the dialogue when switching to Tinker Tom.[verified]
    • To fix this with the console command, enable it and type in prid 000508ed then move close to Tinker Tom and type in moveto player.
  • PCPC Playstation 4Playstation 4 Xbox OneXbox One The quest will occasionally not start after fully completing Hunter/Hunted.[verified]
    • To fix this with the console command, enable it and type in StartQuest MQ206 then SetStage MQ206 10. In addition, if Tinker Tom freezes and doesn't analyse the chip use SetStage MQ206 100.
    • If the console command does not work, check if Sturges is dead. If he is, try console commands to revive or spawn him, then try the command StartQuest MQ206 and SetStage MQ206 10.
    • Console users will have to uninstall quest related mods, reload to before Hunter/Hunted was finished and repeat the quest until it triggers.
  • PCPC Playstation 4Playstation 4 Xbox OneXbox One If the Brotherhood of Steel faction was chosen to assist, Elder Maxson will occasionally teleport inside the hangar where the remnants of Liberty Prime are. This can occur if one is building at Boston Airport, making it impossible to reach him through conventional means. [verified]
    • To fix this, simply build a bed as close to the back wall as possible, then sleep for two hours. If it does not work the first time, simply retry and he should reappear.
  • PCPC Playstation 4Playstation 4 The quest can become bugged when wiring everything. It will keep telling you that the reflector platform is not connected to the circuit, even though it actually is. Storing, rebuilding and wiring everything again should do the trick (or building 3 connecting generators (10 power each) and connecting these to the console. Then connect the beam emitter and the relay dish with the console. [verified]
    • Allow time after storing and rebuilding for the quest to update. If one still has a quest open to build one of the items (even if it has already built,) the quest may not progress even if one has set up the power correctly.
  • PCPC Playstation 4Playstation 4 Xbox OneXbox One Sometimes the stabilized reflector platform will not snap in place with molecular beam emitter. [verified]
  • Playstation 4Playstation 4 If one managed to build multiple signal interceptor parts (possibly due to the quest not properly updating when they are built), the player cannot scrap the unused extras upon their return. [verified]
  • PCPC Xbox OneXbox One In-progress quests cannot be completed or advanced by communicating with Preston, Desdemona, or Maxson until choosing a faction in The Molecular Level. Only faction choice dialogues are available. [verified]
  • PCPC Playstation 4Playstation 4 Sometimes upon placing a part down, the game will not react to it and the quest will become stuck. This can also occur when told to connect all pieces to the same power grid. Storing the part and replacing it does not seem to solve this issue. [verified]
  • PCPC Possible solution if unable to complete the quest after everything is built and connected. The Railroad was assisting faction and Tinker Tom and Desdemona present at the site. Both characters were repeating their dialogues ("And we are in business." for Tinker Tom). Console commands below allowed to finish the quest and player to be relayed to The Institute. The player was standing on the reflector platform when commands were given. Console was closed after each command and opened again for next one. [verified]
    • SetStage MQ206 400
    • SetStage MQ206 500
    • SetStage MQ206 600
    • SetStage MQ206 700
    • SetStage MQ206 1000
  • PCPC It is possible during stage 200 that Preston will not offer any dialogue related to the Signal Interceptor even though the quest indicates him as a quest target "(Optional) Talk to the Minutemen". This bug cannot be fixed by any means and there is no way to build the Signal Interceptor with the Minutemen.
  • Xbox OneXbox One Sometimes, upon teleporting into the Institute for the first time, there will only be a white screen or a blur star obscuring view. This is is a graphics bug and a sign that the save file is corrupt. Uninstalling and reinstalling the game with new saves is the only solution. [verification overdue]