In September 1944, Teuntje Visser works in the office of a
collaborationist mayor in
German-occupied Zeeland as the Allies approach from
Belgium. While she and her father, a doctor, choose to be neutral, her younger brother Dirk is a member of the
Dutch Resistance who is arrested for throwing a rock at a German convoy and betrays the names of other Resistance members under torture. Marinus van Staveren, a
Dutch volunteer in the
Waffen-SS Division Das Reich, is reassigned from the
Eastern Front to serve as secretary and translator for the German commandant in Zeeland, Oberst Berghof. Marinus grows increasingly disillusioned with the Nazis' heavy-handed occupation including the execution of civilian hostages. He sympathises with Teuntje and her father as they attempt to negotiate a lighter sentence for Dirk in Berghof's office. Despite assurances that Dirk will be treated leniently, Berghof ultimately orders Dirk's execution with the other Resistance members. Marinus tries to secretly inform Teuntje but they are spotted by a passing officer, who reports him to Berghof. As punishment, he is assigned to the
firing squad for Dirk's execution, then returned to combat duty. Dirk's death draws Teuntje into the Resistance and she learns Dirk had covertly photographed German positions along the
Scheldt river. Teuntje steals a tidal map of the
Sloe Channel from the mayor's office showing a section of channel deep enough for Allied forces to cross by boat. She is tasked, with her best friend Janna, to smuggle the map and photographs to the Allied forces advancing on
Walcheren island.
Glider Pilot Regiment Sergeant Will Sinclair, Lieutenant Tony Turner, and
Free Dutch Forces soldier Henk Sneijder crash-land in a flooded estuary in Zeeland after their
Airspeed Horsa glider is hit by anti-aircraft fire during
Operation Market Garden. Turner is wounded during the crash-landing. After wading through the marshes, they shelter at a farmhouse whose owner informs them that Operation Market Garden has failed and that the
Canadian Army has entered the Netherlands. Setting out for the Canadian lines through flooded terrain, they take shelter but are abandoned the next day by the other members of their unit. During an attack by German soldiers, Turner is killed. Henk, exhausted and unable to swim, is left behind by Sinclair, who reaches the Allied line and joins Canadian forces advancing on Walcheren. Prior to the
Battle of Walcheren Causeway, Teuntje is captured and Janna is shot, but delivers the map to Allied soldiers before dying. Marinus takes part in the German defense of Walcheren Island while Sinclair participates in the Allied attack, a costly frontal assault. A second attack, planned with the map Jenna provided, goes in across the water and strikes the German defences from the flank. Sinclair and Marinus encounter each other in the fighting, briefly hold each other at gunpoint, then let each other go. As the Germans retreat, Marinus kills a German soldier assaulting Teuntje but is shot during the struggle. A grateful Teuntje tends to him, but Marinus dies of his injuries. Sinclair and other Allied soldiers find Marinus' body next to Teuntje, who walks away as the town is liberated. An epilogue mentions that the Allied victory at Walcheren enabled the reopening of the port of
Antwerp to Allied forces and helped contribute to the
Liberation of the Netherlands on 5 May 1945. ==Cast==