From the introduction:
The world of Imperial Measure is dominated by a huge intergalactic Empire, governed by an immortal bureaucracy known as the Imperial Corps.
All citizens of the Empire are constantly monitored, their actions weighed and measured by an anonymous Watcher. Anybody can live forever, but the cost of immortality is different and constantly shifting for every individual.
The simplest accepted understanding is that if a person behaves and acts as a productive member of society, any Imperial Citizen can earn their Imperial Measure within a lifetime, maybe even sooner than that (to minimize the negative impact of any unforeseen fatal accident).
Become a criminal or deviant and you had better make sure it’s a worthwhile endeavor the cost of your life will shoot through the roof, potentially sealing you to whatever fate strikes you in this incarnation.