A non sequitur (English: /nɒn ˈsɛkwɪtər/ non SEK-wit-ər, Classical Latin: [noːn ˈsɛkᶣɪtʊr]; "[it] does not follow") is a conversational literary device, often used for comedic purposes.
It is something said that, because of its apparent lack of meaning relative to what preceded it,[1] seems absurd to the point of being humorous or confusing.
[4] A non sequitur can denote an abrupt, illogical, or unexpected turn in plot or dialogue by including a relatively inappropriate change in manner.
A non sequitur joke sincerely has no explanation, but it reflects the idiosyncrasies, mental frames and alternative world of the particular comic persona.
He gives the example of a strip where "two cows in a field gaze toward burning Chicago, saying 'It seems that agent 6373 had accomplished her mission.