He first enters the Jack Ryan universe in "Without Remorse", which also features police officer Emmet Ryan and his son Jack. Although he does not appear in "Patriot Games", it is later revealed that he was the CIA's liaison with a French black ops unit involved in the campaign against the ULA. He also does not appear in "Red Rabbit", but is mentioned as giving advice to trainees at The Farm, the CIA training facility. He appears briefly in "The Cardinal of the Kremlin", during which he extracts KGB Chairman Gerasimov's wife and daughter from Leningrad after the Chairman decides to defect to the United States. This marks Clark's first published appearance.