The first season's episodes were 30 minutes in length and portrayed Drake as an Irish-American secret agent, possibly working for a secret arm of NATO, who often argued with his superiors about the ethics of his missions.
After a hiatus its creator, Ralph Smart, rethought the concept and with the second season (1964), the episodes ran a full hour and had a new theme tune, entitled "High Wire". Drake had mysteriously lost his American accent and was no longer in conflict with his bosses. In the US the show was retitled Secret Agent and given a theme song, "Secret Agent Man," by Johnnie Rivers, that became a smash hit.
Unlike the James Bond films, which became increasingly fanciful as they became more popular, Danger Man strove for realism, attempting to dramatize believable Cold War tensions. Drake was an operative for M9, a British intelligence department working under the cover of a travel agency. He found himself often in perilous situations which did not always have happy outcomes, and sometimes his duty forced him to make decisions that led to good people suffering unfair consequences. Drake never carried a gun, though he found himself in numerous fights, and what gadgets he used were never inordinately far-fetched. He also, unlike Bond, never got the girl. (McGoohan was notoriously conservative about sex and violence and refused to play any role that contradicted his views.)
Season four featured only two episodes, "Shinda Shima" and "Koroshi", and these were the only two of the whole series to be shot in color. After these episodes were completed McGoohan suddenly announced that he was resigning from the series. The two colour episodes were then cut together and released as a theatrical feature titled Koroshi.
After Danger Man, McGoohan went on to create The Prisoner, whose protagonist Number 6 is thought by some fans to be John Drake. Number 6 is the number given to a secret agent who has mysteriously resigned from his job - just as McGoohan mysteriously resigned from his secret agent role. McGoohan has denied that Number 6 is Drake, although in the surrealist Prisoner episode "The Girl Who Was Death," we see Number 6 meeting with a character called Potter, who was one of Drake's contacts in Danger Man. This may have been a spoof to tease the fans.
Danger Man has remained a part of pop culture consciousness. The band Tears for Fears referred to the character in their song "Swords and Knives," and goth musicians Dead Can Dance titled one of their songs "The Ubiquitous Mr. Lovegrove" after a Danger Man episode. There also appears to be a quick reference made to the show in the Buffy the Vampire Slayer episode "Never Kill a Boy on the First Date". On UK screens, it was parodied by the Danger Mouse cartoon series.
Seasons two through four of the series are available on DVD.