Some shows and movies are part of the cultural lexicon because they’re easy. If I say “Die Hard on The Love Boat” or “Sopranos meets The Hobbit”, you know exactly what you’re getting. But there is a second kind of entertainment in our pop-culture DNA, shows and movies that are hard because they challenge viewers and carve their own mind space out of the status-quo. The Prisoner, starring, produced and written by Patrick McGoohan, is one of those shows. This September will mark the 50th anniversary of the British television series and, despite having completed its 17-episode run almost a lifetime ago, you can find its fingerprints all over difficult, challenging, brilliant television to this day.

The premise of The Prisoner is deceptively simple: McGoohan’s spy character, probably the same spy that he played in the family-friendly James Bond knockoff Danger Man (aka Secret Agent), is kidnapped and imprisoned in a surreal, brightly-colored dystopia known only as The Village, where he is unwillingly designated Number Six. In most episodes, a sinister authority figure designated Number Two (but played by a different actor than the last episode’s Number Two) tries to get Number Six to reveal his spy secrets.

The plot is novel and interesting, but it’s the execution that has left a permanent mark on the television landscape. The Prisoner’s visual language is highly stylized. Number Six’s monochromatic wardrobe is in direct contrast to the garish colors worn by the other Village residents, and is emphasized by stark gel lighting. Quaint seaside amusement parks give way to villain lairs straight out of James Bond, but lit for the stage complete with a questionably-diegetic tracking spotlight. The score is blaring, obtrusive, dissonant and disorienting. The dialogue is choppy, the writing is surreal, and many scenes are straight-up hallucinogenic -- Number Six may or may not be a reliable narrator, depending on who you believe.

You can find that surreal, unreliable legacy all over modern television if you know what to look for. Sometimes the references are direct: Tricia Helfer’s Battlestar Galactica character was called Number Six as a direct reference to The Prisoner, as her character was to Gaius Baltar as Number Two was to the original Six -- an insidious corruptor, a mind-fucker who tries to get her target to reveal state secrets, and a character that may or may not actually be real depending on the day and setting. (Sadly Baltar wasn’t made of the same stuff as McGoohan’s Six or (spoiler alert) the human race might have survived the Cylon genocide. Then again, none of The Prisoner’s Number Twos could wear a red dress quite like Tricia Helfer.)

The gonzo, ludicrous, balls-out insane Aussie adventure show Danger 5 -- hard to find in the US but so incredibly worth it -- also wears its debt to The Prisoner in plain sight. The show is centered around a multinational team of operatives assigned to kill Hitler, and the team leader, Colonel Chestbridge, wears the same distinct white-bordered blazer as Number Six did. But Danger 5 owes more than its sartorial choices to The Prisoner: It’s shot in an anachronistic style as if it were out of the Technicolor ‘60s. Major elements of the surreal tone and production design are a deliberately low-fi take on The Prisoner’s aesthetic, albeit remixed with Nazi dinosaurs and giant robots, then fed hard drugs and cranked to 11.

Not every show that remixes The Prisoner is as overt in their homage as BSG or Danger 5, but that doesn’t mean they don’t owe a lot to McGoohan’s vision. Perhaps one of the most Prisoner-like shows on TV right now is FX’s Legion. Legion is drawing critical acclaim (though, sadly, not high ratings) for its highly stylized cinematography and production design, arcane dialogue and surreal, dreamlike atmosphere. Many of these elements seem straight from The Prisoner, as do major plot elements. David, Legion’s main character, is both figuratively and at times literally a prisoner, trying to keep his secrets away from a series of enemies and putative friends, some of which may or may not actually exist and some of whom perform spontaneous, inexplicable musical sequences. Clockworks, Summerland, and David’s mental landscape, all vital locations in Legion, draw visual cues from The Village, in some cases down to the color choices and lighting. It may not be a direct lift -- it might be The Prisoner as filtered through Stanley Kubrick and Wes Anderson -- but if you watch the two shows back-to-back the commonalities are undeniable.

You can’t define Legion as “The Prisoner with mutants”, Danger 5 as “The Prisoner with a time-traveling Hitler” or Battlestar as “The Prisoner with sexy fundamentalist murder robots” because by its very nature The Prisoner is tough to define. It’s like trying to grab a wet bar of soap - the harder you squeeze, the more likely it is to shoot out of your hands. The show was often aggressively incoherent because McGoohan, as both star and showrunner, conceived of it as an act of rebellion, a direct response to spy stories that came out of a conformist, dehumanizing, violent, sexist culture -- it’s not an accident that Six is just one ordinal away from 007. It would be unusual and challenging even today -- fifty years ago, when most of television was a treacly pablum, it was a blinding revelation. McGoohan’s character refused to be pushed, filed, stamped, indexed, briefed, debriefed or numbered, and so did his show.