feeding on the base's nuclear-generated power. The invisible creatures eventually attack and kill the military personnel at the airbase in order to take over control of the radar station's nuclear reactor; two of them dial-up the power to very dangerous levels. As they do so all the creatures suddenly become visible. Their now visible bodies are revealed to be the missing brains with spinal cords stolen from their victims; their spinal cords have become very flexible and have now sprouted tendrils. These mutations also allow the brain-spine creatures to move quickly and even leap distances; each brain-spine has also developed a pair of small eyes at the ends of extended eye stalks. The slithering creations then attack Walgate's home, where most of the film's principal characters have gathered to discuss the crisis. Some of the brains get inside by breaking through a boarded-up window using their tendrils, while others leap to the roof and slither down through the fireplace's open flue. Some of the defenders are attacked and killed, but well-aimed .45 semi-automatic pistol shots to the brains soon make short work of most of the attacking creatures; they gorily bleed out as they expire. Walgate exits his home as a diversion, but is quickly attacked and killed by his creation. Meanwhile, Major Cummings escapes out the back way and quickly heads to the airbase, where he saves the day by blowing up the radar installation's power machinery. This immediately robs the surviving brains of their high-energy food source, and the creatures quickly die, dissolving into puddles of goo. Cast Marshall Thompson as Major Jeff Cummings Kynaston Reeves as Professor R. E. Walgate Michael Balfour as Sergeant Kasper Kim Parker as Barbara Griselle Terry Kilburn as Captain Al Chester Gil Winfield as Dr. Warren, M.D. Shane Cordell as Nurse Stanley Maxted as Colonel G. Butler James Dyrenforth as Mayor Hawkins Kerrigan Prescott as Peterson Meadows White & Lala Lloyd as Ben & Amelia Adams Robert MacKenzie as Const. Gibbons Production and release Noted science fiction personality, collector, and literary agent Forrest J Ackerman represented mystery and science fiction pulp writer Long and brokered the sale of her story "The Thought Monster" to the film's producers. Screenwriter Leder was originally set to direct the film, but being American, was unable to obtain a British work permit in time, so Crabtree replaced him as director. Thompson later said that when the director