Primer - Ghosts.

Ghosts are the soldiers that don't exist. They are cutting edge
hybrids made of flesh and cybernetic augments. Their minds have been
trained in the use of their new bodies and if their training alone
wasn't enough their ability to manifest a deadly psionic blade at
will that harms not flesh but a victim’s mind itself is truly
terrifying.

No Ghost began as a Ghost. They all began as soldiers for the New
Republic who distinguished themselves for their specialization,
loyalty and drive. Most found themselves on deaths door offered the
chance to return to service but to loose who they were before. Those
who agreed were given new bodies that were hybrid forms of cyberwear
and bioware. They were re-trained and re-focused to wield latent
psionic powers and sent forth to do the New Republics most important
missions.

A series of linked implants became the hallmark of a Ghost, primarily
a special socket at the base of the neck. It was discovered early on
that the unique configuration of implanted hardware would allow
Ghosts to record their experiences and memories. Adapting quickly to
the profound discovery it soon become common policy for new Ghosts to
slave in mentor Ghosts' and relive their careers, learning from
entire lives.

Vast libraries of Ghosts cores began to be compiled and before long
they were collected into networked Nodes. This allowed Ghosts to
access a sort "GhostNet" as it came to be known. The pure knowledge
of experience and memory could be accessed by a Ghost for counsel or
research.

But soon the fragmenting New Republic began to fear the resource and
attempted to destroy Core Archives and Nodes. GhostNet was forced to
go underground in order to preserve itself. Even now isolated Nodes
exist hidden in the reaches of the Rim and scattered preserving
everything they can. Some even whisper it is GhostNet itself that
will occasionally leak news events straight from those who
experienced it to public Nodes, ensuring some truths remain unhidden
and unaltered.