Screamers is a 1995 dystopian science fiction/action film starring Peter Weller, Roy Dupuis, and Jennifer Rubin, and directed by Christian Duguay. The screenplay, written by Dan O'Bannon with a rewrite by Miguel Tejada-Flores, is based on Philip K. Dick's short story "Second Variety", and addresses themes commonly found in that author's work: societal conflict, confusion of reality and illusion, and machines turning upon their creators. The year is 2078. The planet Sirius 6B, once a thriving mining hub, has been reduced to a toxic wasteland by a civil war between the Alliance, a resistance group composed of the colony's former mining and science personnel, and their employers, the New Economic Block (NEB). Five years into the war, Alliance scientists created and deployed Autonomous Mobile Swords (AMS) — artificially intelligent self-replicating machines that hunt down and kill NEB soldiers on their own. They are nicknamed "screamers" because of the high-pitched noise they emit as they attack. Screamers cannot distinguish friend from foe; they track targets by their heartbeats, so Alliance soldiers wear "tabs" which broadcast a signal canceling out the wearer's heartbeat and rendering them "invisible" to the machines.