This paper examines how the Polish communist intelligence service attempted to recruit professor Stefan Węgrzyn, who was a prominent specialist on automatic control and computer science in post-war Poland. Eventually, Węgrzyn’s refusal to cooperate with the Polish spy agency, together with his profound relationship with French scientist and servomechanism expert Jean Charles Gille, made them both targets of surveillance orchestrated by the communist security apparatus.In the broader context of human-intelligence studies, this case study involves the problem of moral ambiguity. We experience informative examples of scientists, who often – not only during the Cold War – have had to choose between commitment to the rules of the academic world, along with its openness and transparency on the one hand, and patriotism including an ethos of secrecy for the sake of the homeland’s prosperity, on the other hand.