In a future human society, people are highly dependent on robots. These robots are divided into three classes. The Dum class, black robots, are single-function labor robots without voice capability. The Voc class, gold robots, are in charge of higher-level jobs that require vocal communication; for example, they man the controls of the sandminer during periods of low activity. The Super-Voc class, silver robots, are the co-ordinators, in command of all Vocs and Dums; there is only one, SV7, on board the sandminer. Each robot is assigned a designation, consisting of class and an individual number, which is displayed on the chest. The faceplate and hands of a robot are removable, and probably most of the rest is, as well - possibly this is to enable easier service and repair. The robots are equipped with voice recognition, and they can communicate with one another via the command circuit, although commands are primarily sent out by a Super-Voc.
Although robots are ubiquitous in this society, many people experience robophobia, aka Grimwade's syndrome. This is probably because, unlike humans, robots give off no body language and are thus reminiscent of the walking dead. Such fears are only reinforced by urban legends, such as the tale of a Voc therapist that cured a patient's stiff elbow by ripping off his arm.
A commonly-quoted rule is that robots cannot possibly harm humans - it is the primary rule programmed into their command codes. There are over one million multi-level constrainers in a Voc's program that prohibit such things from happening. But command codes can be restructured, particularly by a robot scientist as talented as Taren Capel. Having lived with only robots from childhood, Capel was on a mission to free his "brothers" from human oppression, and sought to achieve this by killing off the human population. Robots under Capel's control could be distinguished from "friendly" robots by virtue of the staticky red eyes that resulted from a command code alteration. Capel used a Laserson probe to reprogram the robots - these handy and precise tools have the capability to punch a fist-sized hole in six-inch armor plate or take the crystals from a snowflake one by one. When used less precisely, they can severely damage mechanical and organic circuitry.
Those murdered by Capel's robots were decorated with a glittery red disc known colloquially as a "corpse marker". Actually a robot deactivation disc, they were used in construction centers to mark robots that had been deactivated and were awaiting repair and reactivation.
The robots are extremely strong, throttling humans with their bare hands. They are also very fast, and they never tire. They are susceptible to explosives, but knives and karate moves do them no harm.
