Government agent Lemmy Caution (Eddie Constantine) is dispatched on a secret mission to Alphaville, a dystopian metropolis in a distant corner of the galaxy. Caution is hot on the trail of rogue agent Henri Dickson (Akim Tamiroff) and a scientist named Von Braun, the creator of Alpha 60, a computer that uses mind control to rule over residents of Alphaville. Caution is aided in his quest to destroy the despotic computer ruler by Von Braun’s own daughter, Natacha (Anna Karina).