Gemini Man Henry Brogan is a 51-year old former Force Recon Marine Scout Sniper who works as an assassin at the Defense Intelligence Agency. Henry Brogan is the one responsible for the death of a bio-terrorist who was killed on the train in Belgium. His spotter informs him that a young girl is approaching his intended target. Henry was not thrilled with the thought of shooting the man’s neck.
Henry is introduced to Danny, the manager of the company that rents boats located in Buttermilk Sound in Georgia. He reunites with Jack who was his former acquaintance, and discovers that Yuri the informant claims that the victim in the train attack was innocent. Lassiter, the agency director, is then able to murder Henry. Clay Varris is director of the criminal private army corporation known as “GEMINI” however, he is not granted permission.
Henry discovers that Danny is an agent for the government. He observes his work. Henry becomes friends with her , and utilizes his spotter as a telephone number to call the government when his house is attacked by government agents. Jack and his mistress are also murdered. Henry warns Danny, and they shoot the assassins that chase them. They discover that the agency wants both of them to die.
Henry and Danny escape Danny and Henry escape to Colombia with Baron Henry’s former coworker who’s hiding at Baron’s residence and planning to meet Yuri. Clay sends in his most skilled assassin to eliminate Henry. Fighting him off, Henry realizes the assassin has a striking resemblance to his former self as a young man. The assassin is escorted to an uninvolved location and exposed to Clay’s adopted son Junior. Confounded by the similarities between him and Henry, Junior is ordered to complete the task.
Danny thinks that the person who killed him may be Henry’s son even though Henry denies it. In search of clarification, Henry has Baron obtain an Gulfstream and bring the dead to Hungary. Testing DNA recovered from Junior, Danny discovers that Henry’s DNA and Junior’s are the same – Junior is Henry’s clone. Henry gets together with Yuri to find out more about the GEMINI cloning program. Scientists who developed the idea of creating replicas that were free of pain and emotion was the one who was killed.
Henry calls Lassiter who agrees to dispatch Junior to assist in bringing Danny safe back to the United States. After capturing Danny, Junior sets up an escape plan for Henry and he is warned via the use of a hidden device for listening that is hidden inside Danny’s mouth. Junior is confronted by Henry and he tells Junior that they are both clones of each other, and share the same characteristics.
Junior escapes from GEMINI, confronting Clay who claims that the only method to be victorious is to defeat Henry. Junior knocks Clay unconscious during a hand-to-hand combat.
Henry, Danny and Junior fight off a group of GEMINI operatives. The trio must now confront an operative who appears to be invincible equipped with special body armor. They are able to mortally wound the man, and then he’s identified as a younger version of Henry who lacks emotions and the capacity to feel pain. Clay is defeated and attempts to defend himself before Junior. Junior is distraught and has plans to murder Clay. However, Henry convinces him to keep away and shoots Clay.
Henry is confident that there will be no more replicas created, and they are now free. Junior is later introduced to Henry who has been enrolled at the college under the pseudonym “Jackson Brogan” which is named after Henry’s mother. Henry and Danny are capable of working together on plans for Jackson’s future.