In the fictional dystopia depicted in the "Matrix" trilogy of films directed by the Wachowskis in the late 1990s and early 2000s, the basic scenario is that reality is a computer-generated illusion, and that a giant artificial-intelligence network has taken over Earth and reduced humans to comatose husks deluded by data, who are kept alive only to provide body heat and electrical energy that can be siphoned off to power the network. Not all humans are down with that, however, and a motley assortment of meat-body rebels -- including a superhuman savior-prodigy named Neo, portrayed by Keanu Reeves -- persist in doing battle with the Matrix and its robotic minions [source: Greenwood].
Perhaps the scariest of the latter are the Sentinels -- giant cephalopod-like automatons -- who are sent down into the sewers and underground passageways of long-dead human cities to stalk human rebels and destroy them. In one of the more intriguing life-imitates-art twists in technology, a Glasgow, Scotland-based company named Breval in 2007 unveiled an actual robot modeled after the Sentinels. Breval's Wizard robot, however, is much smaller than the Sentinels, and equipped with eight wheels rather than metal feelers. More importantly, its mission is to clear ventilation ducts of bacteria and other contaminants, not humans [source: Christensen].