An AI computer virus called Venjix takes over all of the Earth's computers, creates an army of robot "Grinder" droids and destroys or enslaves almost all of humanity. Only the city of Corinth remains, protected by an almost impenetrable force field from the toxic atmosphere of the wasteland outside. Venjix tries various plans to destroy Corinth, and Doctor K's RPM Power Rangers fight to protect it. The Power Rangers Samurai two-part episode Clash of the Red Rangers, a crossover with RPM, establishes that RPM is actually in an alternate universe to the other seasons of the Power Rangers franchise.