Poul was a renowned ship builder in the employ of the Galactic Union Marine Corp, having 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; 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 is considered highly classified, and Isaac's continuous attempts to locate him have been rebuffed.
While his current location is unknown, his relationship with Isaac and the nature of his classified work has led many fans to speculate he will somehow play a larger role in future installments, though this is unconfirmed.
Unknown to Isaac, the government has 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.