Early Soviet victories forced the North American government and production to flee to a Moon base, leaving the majority of their troops behind.
To counter the almost complete Soviet victory, U.N. technicians develop robots, nicknamed "claws" —the basic models are "a churning sphere of blades and metal" that ambush their unsuspecting victims "spinning, creeping, shaking themselves up suddenly from the gray ash and darting toward… [any warm body]."
Within six years, the sophisticated and independent claws have destroyed the Soviet forces, repairing and redesigning themselves in underground automated factories run without any human oversight.
From salvaged internal metal identification plates, two varieties are identified: I-V, a wounded soldier, and III-V, David.
Noticing the bombs carried by all the Tasso models, Hendricks' final thought is that the robots are already producing weapons designed for killing each other.
[4] It has since been republished in the following collections: A Canadian film based on "Second Variety", titled Screamers, was made in 1995, featuring Peter Weller.
Produced after the fall of the Soviet Union, the film employs a new backstory involving a proxy war between disgruntled miners and mercenaries over working conditions on a hostile planet.
Jason P. Vest, in Future Imperfect: Philip K. Dick at the Movies, writes that the film is more faithful than most other adaptations, but it received a mixed critical reception and failed at the box office.