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
After the Institute began creating advanced synthetic humans ("synths") around 2227, many developed strong personalities and a desire to escape their life of servitude. Despite their apparent ability to feel and think freely, synths are treated as slaves in the Institute, only utilized for maintenance and security purposes. 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.
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 advanced synths with incredible combat capabilities and dulled personalities known as coursers, designed to track down and reclaim escaped synths at all costs. Due to the effectiveness and brutality of the coursers' methods, the S.R.B. is feared by all escaped synths, and even by some of the synths and scientists within the Institute itself.
- Sole Survivor (determinant)
- Justin Ayo
- McDonough (also known as M7-62)
- Harkness (former courser, originally designated A3-21)
- Alana Secord
- Numerous coursers