An American physicist and rocket scientist, Michael Armstrong, embarks on a journey to an international scientific conference in Copenhagen accompanied by his assistant and fiancée, Sarah Sherman. However, Sarah becomes suspicious when she discovers a cryptic message in Michael's handwriting, which suggests that he may be defecting to East Germany. Her fears are confirmed when Michael publicly declares his intention to defect upon their arrival, leaving Sarah heartbroken and bewildered by his sudden betrayal of their country.

While Michael's defection is initially met with praise from the East German government, tensions quickly escalate as it becomes apparent that not everything is as it seems. Sarah, determined to uncover the truth behind Michael's actions, follows him across the Iron Curtain. There, the couple finds themselves entangled in a web of espionage and duplicity, struggling to navigate a treacherous world where friend and foe are indistinguishable. As they delve deeper into the intrigue, the layers of deception peel away, revealing a high-stakes game of intelligence and counter-intelligence.