A car pulls up to an abandoned military base and four men get out. The Recruiter tells the security guard they're okay, and the other three men--Luis D. Spain, Genero Planetta, and Henry Castle--go into the nearby building. Genero them trips over a standing astray and Luis looks back at him briefly, smiling sympathetically. As they move on, a man peers at them from a doorway. Once they move on, the man, Larry Hillmond, walks to a morgue. Thing move within the drawers, making low growling noises, and Hillmond removes a large alien parasite from one drawer. He puts it on a nearby table, stroking it gently, and then clutches at himself and addresses his "master", saying that they're whole.
Later, Hillmond addresses the three recruits, explaining that they have voluntarily joined "The Invisibles". It is subversive, illegal, and powerful... and it is ready, and the recruits will become the elite of the new society. Hillmond invites them to ask questions, and Genero asks if they'll work together. He's informed that they will work in separate cities and have no contact with each other. Luis asks when they'll see the Invisibles, and Hillmond assures him that he'll see them. He then says that "they" were created in space and formed from stellar energy over a billion years. The Invisibles fell to Earth and started the evolution of their primitive form. Hillmond warns that the Invisibles take their victims to the edge of death. Luis realizes that Hillmond is a state governor, but Hillmond tells him that he is now the ruler of the Invisibles, nothing less.
The Recruiter comes in and gives each recruit an inoculation. Hillmond explains that the injections are to protect them accidental infection. The Invisibles will attack any human except one who has already been invaded. Since the three recruits aren't important enough to be hosts, they're immunized against the Invisibles that they'll carry to those who are targets. Hillmond explains that at midnight they will each be exposed to an Invisible. If the inoculation is successful than nothing will happen.
That night, the three recruits try to sleep while screams echo throughout the compound. When Genero panics, Luis muzzles him until the younger man gets control. The screams stop, and Luis looks outside and then tells Genero that Castle was the one screaming. Castle is in the outside hallway and there's something underneath his shirt on his back. Genero suggests that the two of them run away, and Luis says that once the Invisibles take over, they'll be something.
The Recruiter comes in and tells Genero to follow him. Genero hesitates and Luis suggests that the two of them go together. The Recruiter tells them that Castle's inoculation failed and the Invisible isn't supposed to show, and they can't afford to lose another one of them. Luis and Genero follow the Recruiter to the morgue, and the Recruiter makes a small nick on Genero's naked back. Hillmond then puts the Invisible on Genero's back, and he rolls and knocks it onto the floor. Laughing in relief, Genero realizes that he's uninfected. Hillmond then repeats the same procedure with Luis, who doesn't flinch and is also uninfected.
Later, Luis crawls out the window of his room and slips off the base. He enters the forest and meets with his contact, Johnny. Luis describes what happened to his fellow GIA intelligence agent, and records a voice report as Agent 0021, and describes what happened and what the Invisibles plan. Indoctrination classes begin the next morning and Luis has no idea where they will be. Luis reports that he's trying to win Genero over, and if successful then the GIA will hear from him with more information from Luis. The agent advises treating him as a leper or otherwise the Invisibles will generate the GIA.
The next day, Hillmond indoctrinates Luis, Genero, and other recruits. They will be given jobs with their targets, and will infect the targets when opportunities arise. If any of the recruits contact someone unknown to the Invisibles, they'll be murdered. Once Hillmond leaves, the Recruiter tells them that the next class will take place at the morgue and they'll be taught how to perform the attachment operation on a new specimen.
In the morgue, Luis and the others discover that Johnny is the new specimen. The Supervisor explains the attachment process, and the Recruiter puts an Invisible on Johnny's back. The Invisibles can't invade a dead man: the Supervisor is using the corpse to demonstrate.
Back in the dorm, Luis tells Genero that he was thinking about a friend of his who got killed in a war, and he had the same boots as Johnny. Genero wonders if Luis would ever lie to him if they were friends, and Luis says that Genero can never be his friend because they can never see each other after they leave. The younger man tells Luis not act like he likes him when he doesn't, and Luis says that Genero reminds him of his kid brother. He then tells Genero to call his brother and say where he is, and then Luis will contact him and look Genero up and they can have a night on the town. Luis assures Genero that the threats of surveillance are just scare tactics, and Genero agrees. The undercover agent gives Genero a phone number to call.
Later, Hillmond gives each recruit a case holding an Invisible and an envelope with their assignment. Luis goes to a waiting car and the Recruiter informs him that his job is a chauffeur to General Hillary J. Clarke in DC. Castle comes out and looks briefly at Luis, and then limps away.
The next day, Luis assumes his new job. He drives Mrs. Clarke around, and she says that her husband will be coming home that night. Luis then goes to smoke and runs into Oliver Fair, Mrs. Clarke's social secretary. Oliver asks if they can talk privately, saying that Clarke hired him on his recommendation. Luis refuses and Oliver says that Clarke will be there that night and Oliver will keep Mrs. Clarke downstairs for an hour or more. He says that he'll watch Luis every minute, and admits that Luis is being a good boy so far.
Luis drives Mrs. Clarke to what she claims is her doctor's appointment, and stops when the engine apparently breaks down. He offers to call the doctor when he goes to the next gas station, but Mrs. Clarke says that it won't be necessary. Luis goes to a phone booth and calls in to his superiors. He confirms that Johnny handed over the tapes but Genero hasn't called. The GIA has determined that Genero is in DC working at a water treatment plant. Oliver watches from hiding as Luis's superior tells him that Clarke is getting in that night and they can't stall him. Luis warns that his inoculation runs out that night, and they'll have to give him a new one that night. The agent continues on to the station, and Oliver goes to his car and radios to his superior that Luis made a phone call. He says that Luis will be ready that night.
That night, Oliver goes to Clarke's study and offers to show him Luis. Luis comes in and Oliver excuses himself. Clarke asks if Luis is a friend or foe, and tells him to note all of Mrs. Clarke's destinations. Luis refuses and Clarke seemingly accepts his refusal. He tells Luis not to pity him as Luis goes. He then adjusts his intercom. Luis comes back in, claiming that he forgot his cap, and Oliver comes on the intercom irritably demanding to know what's going on. Clarke tells him that he approves of the new chauffeur and then tells Luis that his wife's social secretary would never talk to him that way. The general draws a gun on Luis and tells Oliver to bring the invisible.
Clarke explains that they suspected Luis was an agent so he was assigned to Clarke. Now they'll have an Invisible in the GIA, now that Luis' inoculation has worn off. Clarke boasts of how it's happening all fast and rattles off the names of other hosts. He moans in pain, calling to his "master", and admits that he's vainglorious and says too much. After a moment Clarke looks up and discovers that Luis has fled. Oliver comes in and tells Clarke that Luis managed to kill the Invisible they intended for him.
Mrs. Clarke pulls up and hits Luis as he flees the house, catching his ankle in the wheel well. She goes to get her husband despite Luis' protests, and Luis pulls his ankle free but passes out from the pain. When he wakes up, he finds himself on a bed in the Clarke house.
Oliver calls in to get another Invisible, and tells Clarke that they need to keep Luis agent so they can make him a double agent. Clarke worries that Mrs. Clarke will find out something, and Oliver assures him that he controls her.
Luis gets up despite his injury and crawls to the door. Mrs. Clarke comes in and wraps Luis' ankle, He asks why she doesn't call the police ambulance, and she says that Oliver has tapes of her and a "friend", and Oliver is blackmailing her to assure her silence. Luis tells her to put his shoe back on and she does so despite his obvious agony. He passes out and Mrs. Clarke gets him a pillow and leaves.
The next morning, Oliver takes photos of government plans and hears a car driving off. He looks out and sees Luis at the wheel, and drives after him. Oliver finally finds Luis' abandoned car. Meanwhile, Luis hobbles to the nearby water treatment plant and a worker direct him to Genero. Once Luis moves on, the worker makes a phone call.
Luis finds Genero, who helps him into a shed. A case holding an Invisible is beneath Genero's bed, and Genero says that he has to get to GIA headquarters in Virginia. When he realizes that he can't walk, he asks Genero to make a call and passes out. When Genero recites his memorized orders to infect Luis, Luis wakes up and realizes that he's the target. Genero takes out the Invisible and prepares to put it on Luis. He says that he didn't want it but they told him that Luis is an agent and realized that Luis lied to him. Luis gets up, insisting that he was trying to help Genero, and collapses to the floor. Genero tosses the Invisible at Luis and runs out.
Luis crawls away from the slowly-advancing Invisible, gets to his feet, and limps outside. He collapses and sees Genero walking away, and the Invisible comes out after Luis. Luis begs Genero for help, and police sirens sound. Genero runs back to Luis where the Invisible has crawled onto the agent's back, and Genero tries to pull it off. The police and the GIA agent with them shoot Genero, but he manages to pull off the Invisible and toss it away, and the police kill it. The workers--a GIA agent--assures Luis that they'll find all of the hosts. They've captured Oliver and he's "cooperating", and the GIA agents help Luis away.
Written by Gadfly on Jan 30, 2018