Poul was a renowned ship builder in the employ of the Galactic Union Marine Corp. He amassed a considerable estate in addition to multiple awards and commendations.
Due to the nature of his work, Poul was away from his family for extended periods of time which was the only break in this being when Poul was reassigned to Earth during Isaac's first four years of life. Upon completion of this tour, Poul went on an extended off-world tour during which he seemingly vanished. His service record was considered highly classified and Isaac's continuous attempts to locate him are rebuffed.
While his current location was unknown, his relationship with Isaac and the nature of his classified work led many fans to speculate that he would somehow play a larger role in future installments, though this was unconfirmed.
Unknown to Isaac, the government had files on his father classified as "Top Secret".
- Like his wife and son the name Poul Clarke references two revered science fiction writers: Poul Anderson and Arthur C. Clarke.