A virtual remake of the earlier The Purple Monster Strikes (1945) and containing an overabundance of stock footage from that serial and G-Men vs. the Black Dragon (1943), this 12 chapter science fiction serial from Republic Pictures featured former RKO contract player Walter Reed as owner of an air patrol company. Along with his lovely secretary, (Lois Collier), Reed is looking into the mysterious doings of a certain Dr. Bryant (James Craven). As it turns out, the good doctor is under the spell of none other than Mota (Gregory Gay), a visiting Martian in search of uranium and other materials needed to power his ferocious weapons of war. Establishing himself in the crater of a volcano, Mota embarks on a terror campaign against the earthlings which seemingly only Reed's Fowler Air Patrol is able to counter. In the end, both Mota and Dr. Bryant are destroyed by one of their own atomic bombs, leaving Reed and Collier able to plan a less stressful future. Cashing in on the enormous popularity of sci-fi in the late '50s, this serial was re-edited and released as a feature film under the new title Missile Monsters. Villain James Craven had played the same role in the earlier The Purple Monster Strikes and was obviously cast in order to match the stock-footage. Roy Barcroft, who had played the title role in "Purple Monster," did not repeat, however, but was still very visible in the re-edited footage.