Synopsis by Bruce Eder
Dr. Peter Brady (Tim Turner), a physicist working for a British government laboratory on a problem concerning light refraction, receives an overdose of radiation during an experiment that renders him invisible. At first, his superiors, unable to know what to make of this tragedy/miracle, try to keep him under wraps -- but Brady won't be held a prisoner, nor does he intend to remain invisible a second longer than it takes him to find a solution to his problem, and he escapes their custody, returning to the home of his astonished widowed sister (Lisa Daniely) and her daughter (Deborah Watling). After some verbal and physical jousting with his superiors, it's agreed that Brady's condition and situation will remain a top secret, but that he will be free to come and go as he pleases, while trying to find a cure for his condition. This accommodation works for a time, and Brady does voluntarily go to work on behalf of the government on various espionage and rescue missions, although enough people -- both in and out of the government -- gradually come to learn about his condition, so that he isn't much more of a "secret" than James Bond's real work is a "secret" to anyone but the surrounding ordinary public. His condition does become public knowledge by accident midway through the run of the 26-episode series, and he ends up as an unwilling celebrity, with the police and ordinary people coming to him for help after that. Actor Tim Turner, who played Brady (whose face is never seen) in the opening moments of the first episode and voiced the part for the run of the series, was never credited on the show, nor was his identity revealed until it had been in reruns in England for a half-decade -- as a sort of "in" joke, he actually played a villain on-camera in one episode.