In Paris, Donna Lloyd has been missing for two days. In Dallas, her husband Walter Lloyd and their college-age son Chris decide to look for her. At the airport, Chris bumps into Carla, a backpacker who becomes part of the tense, unfolding chase. Walter, meanwhile, encounters Heinz Henke, a man clutching Donna’s jewelry, while a man wearing glasses aims to kill Walter, only to shoot Henke by mistake and vanish.
At the Paris hotel, Walter confirms that Donna has indeed been kidnapped, a revelation that shifts the mission from casual searching to careful, high-stakes pursuit. Chris soon intervenes when a car fires on Walter, sparing his life and forcing the two to escape. In the aftermath, Walter confesses that he used to work for the CIA, a truth that adds a layer of danger and complexity to their predicament.
Across the story, the CIA keeps a watchful eye on the two, determined to keep them from getting in over their heads. The pair boards a train to Hamburg, managing to dodge the agency’s surveillance along the way. A stop at the train station introduces a curious moment: a man confronts a young man and his father, shouting “Mendelssohn” before grabbing a fiddle and beginning a tune. Walter and Chris move on, but the encounter hints at a code and a deeper conspiracy at play. Later, Chris notices Clara—another figure who will appear again in their precarious odyssey.
The next day brings a meeting with “The Colonel,” Walter’s old supervisor, who holds fragments of the past that could influence their future. Chris spots the fiddler again, prompting Walter to speed away in a car. The pursuit intensifies; when they cannot outrun it, Walter abandons Chris and makes a break for safety on foot. Cornered by the fiddler and another agent, Walter leaps from the pier onto a passing ferry. The assassins murmur the tune as they guide him toward a rendezvous, and the killer who had previously tried to end Walter’s life eliminates the fiddler when the moment demands. Chris eventually reunites with Walter, pulling him to safety.
A conversation at The Colonel’s place reveals more about Henke’s fate and a shadowy past. They recall “Operation Clean Sweep,” a botched mission in which five of six agents were killed. The Mendelssohn motif has one more meaning: it was the codename Schroeder, the agent who escaped that fateful operation. The tension deepens as Walter travels north to West Berlin, while Chris heads toward Frankfurt, each step seemingly aimed at keeping the other alive.
Meanwhile, the assassin returns, forcing the Colonel to endure torture in an attempt to divulge the Lloyds’ whereabouts. Although the Colonel resists, his caretaker betrays him, and both are killed, leaving a darker shadow over the operation and a clearer target for Walter and Chris.
At a US Embassy in Berlin, Chris is directed by Walter to move toward an abandoned air force base—an old CIA exchange point for captured agents. Chris forges ahead into East Berlin, where the embassy’s director Barney Taber and agent Clay close in. Walter and Taber exchange tense words while Chris discovers Donna bound and wrapped in plastic explosives in a nearby hangar. The tension reaches a crescendo as Walter and Clay race to defuse the perilous device, but Taber’s double-dealing comes to light. Taber shoots Clay, and Schroeder suddenly reappears, complicating the plot further. Schroeder helps to evacuate the Lloyds but then detonates the explosives along with Taber, bringing the dangerous pursuit to a fatal and explosive close.
