Complex sentence: Byrd is a janitor in a NASA laboratory headed by Major General Smithburn (Andrews) with his security officer the bumbling Lt. Porter (Hunter) who is captured and impersonated by an enemy double from the same organisation attempting to kill Byrd.
Split into simpler sentences: Byrd is a janitor in a NASA laboratory headed by Major General Smithburn (Andrews) with his security officer being an inept bungler, Lt. Porter (Hunter). Porter is captured and impersonated by an enemy double from the same organization attempting to kill Byrd.