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My God, I... I remember. I remember it all. From before. Zimmer. The Commonwealth. The Institute. My God, all those runners I brought down...Harkness, after his memory is restored

The Synth Retention Bureau (S.R.B.) is a branch of the Institute tasked with tracking and capturing escaped synths.


After the Institute began creating advanced synthetic humans ("synths") many developed strong personalities and a desire to escape their life of servitude.[1] With the help of Institute synth sympathizers like Liam Binet, and factions like the Railroad, many synths have escaped the Institute, most of them subsequently having their minds wiped and faces reconstructed, allowing them to live lives as normal humans.[2][3]

As a result of the synth escapes, the Institute founded the Synth Retention Bureau, or S.R.B., a branch of the Institute dedicated solely to the recovery and rehabilitation of escaped synths. The Institute scientists developed synths called coursers, designed to track down and reclaim escaped synths.[4] Inside the Institute, the Sole Survivor learns of the tension between the S.R.B and the other divisions (especially Advanced Systems) and that a scientist named William Moseley was employed as a bridge between the two divisions.[5]

Known members

SRB members
Dr. Zimmer Justin Ayo Alana Secord
Field agents
Conrad Kellogg Art M7-62 (Mayor McDonough)
Roger Warwick Sammy Sole Survivor (optional)
S3-47 (Armitage) A3-21 (Harkness) (formerly) Chase (formerly)
X4-18 X6-88 X9-27
Z2-47 B8-88 C8-65
F5-93 G6-43 H7-44
J1-74 J8-28 K0-84
K2-90 K6-70 L7-92
M9-11 P1-77 Q2-87
R6-01 R7-81 T3-54
W4-40 X1-02 X1-91
X2-36 X2-71 X3-24
X3-28 X3-37 X3-51
X5-76 X6-57 X7-55
AJ Cricket Doc Weathers
Henry Cooke Lucas Miller Marowski
Tommy Lonegan Trashcan Carla


Zimmer mentions that Harkness used to work for a "special branch of the Commonwealth Police."[6]


The Synth Retention Bureau appears in Fallout 3 and Fallout 4.



  1. The Lone Wanderer: "Anything else I should know?"
    Victoria Watts: "Just understand that this android is now, for all intents and purposes, a man. He looks human, he acts human. He believes he IS human. But even if he's not... Even if he's a machine... He's capable of rational thought. And emotion. So you see, his soul is as human as yours or mine. This person -- and he is a person -- deserves a chance at freedom. Please, if there's a shred of decency in you, don't take that away from him."
    (Victoria Watts' dialogue)
  2. The Sole Survivor: "Why are you helping synths?"
    Liam Binet: "At first I just wanted to see if I could get away with it. It was a challenge, you know? But then I realized the synths are really just like us, except without any freedom. I decided to help the ones that wanted to escape, so they can have a better life."
    (Liam Binet's dialogue)
  3. Desdemona: "The Institute treats synths as property. As tools."
    The Sole Survivor: "That sounds like slavery."
    Desdemona: "Exactly. So we seek to free the synths from their bondage. Give them a chance at a real life."
    (Desdemona's dialogue)
  4. Justin Ayo: "Coursers hunt down and reclaim synths that have escaped the Institute. They are highly self-sufficient, trained in combat, infiltration and tracking. In a word, our Coursers are relentless. But I gather you know all of this, since you've encountered one already."
    (Justin Ayo's dialogue)
  5. The Sole Survivor: "What's your story, William?"
    William Moseley: "Me? Oh... Uhh, I've been acting as sort of a liason between Advanced Systems and the SRB for a few years now. Doctors Li and Ayo didn't really get along, as I'm sure you can imagine. It worked better if someone could sort of bridge the gap. Anyway, I'm just here trying to do my part."
    (William Moseley's dialogue)
  6. Lone Wanderer: "I've found your android. It's Harkness, Rivet City's security chief!"
    Zimmer: "Harkness, you say? Yes... Yes, that makes sense. He used to work for a special branch of the Commonwealth Police, after all."
    (Zimmer's dialogue)