The story is set three hundred years in the future. After a period of commercial space exploration, and brutal corporate warfare. The Black Knight is the sole survivor of a terrorist attack. He has since become a mercenary for a mining company that has to fight the terrorists on a regular basis. On one hand he's driven by a need for revenge, but is also repulsed by the concept. So he fights with his hands tied, looking for a middle ground between revenge and acquiescence.
The leader of the terrorists is an old friend of the Black Knight. He was set upon the path of destruction by a friendly political debate with the Black Knight. Thus the main character feels responsible for the destruction these terrorists cause.
Both are being manipulated by a secret organization called the Sphere of Influence that controls it's members through the use of nanotechnology. This same nanotechnology makes them practically immortal.
These manipulations are what leads to "The Orphan's Search." A young assassin—an orphan from the corporate wars--approaches the Black Knight's company for help. Her twin is missing. A corporation that deals in weapons appears to be responsible--and they're approaching the Black Knight for a sale. At the same the terrorist group presses them for their territory. Is this a string of strange coincidences or a new and innovative sales pitch? The Black Knight must discover the truth to survive.