Operation Carthage saw allied forces conduct a raid in Copenhagen's center, targeting the Gestapo HQ. 'It was considered one of the most dangerous operations of World War Two’, explains Sven Truelsen, then-chief of Danish military intelligence. Tragically, though the headquarters were destroyed, a school was hit by mistake. 'The raid was 100% successful. But then you have to balance it with the losses', says leader of the operation Ted Sismore.

Yet the imperative to destroy this hub of Nazi activity grew too strong, and the RAF was reluctantly asked by the Danes to attempt a raid on it. "Irrespective of the fact that a lot of close friends were sitting on top of the Shell House, plus the houses and a school on the other side would be hit, we had to ask for help", says Ole Lippman, leader of the Danish resistance.

Air Commodore Ted Sismore was given the unenviable task of leading the operation: success depended on pinpointing one building in the middle of a crowded city. "It was considered one of the most dangerous operations of World War Two", explains Sven Truelsen, the then chief of Danish military intelligence. "My first reaction was: not possible", laughs Ted.

"We flew across the sea at 50ft all the way, just to make sure we didn't get picked up by any radar…" Flying into Denmark in the iconic Mosquito, a plane made almost entirely of wood, the team swept across the countryside "at treetop height". For those on the ground, the sight of the planes brought the hope of freedom. "People in the fields were standing to attention and waving. They were terribly excited. It was very inspiring", one pilot recalls.

"When we entered Copenhagen we came under fire". Dodging attack, the planes flew straight up the river running through the middle of the city and across the streets. They approached the target in three waves of six planes. As the bombs fell and a fire engulfed the building, the attic-bound hostages clambered over bodies to escape.

But the mission was not to be without tragedy: "the smoke from the fire hid the target from those coming up behind", Ted explains. An accidental bombing of the nearby Jeanne D'Arc School resulted in the deaths of 86 children and 13 adults. "Since the object of the raid was to destroy the [Gestapo] documentation, the raid was 100% successful. Then you have to balance it with the losses…How can you balance it?", Ted asks, holding back tears.

Narrated by Martin Sheen, through a combination of dramatic archival footage of the actual raid and revealing interviews with those involved, this short doc provides a poignant picture of war and its penalties.