Czechoslovak patriots Josef Gabcik and Jan Kubis were destined to embark on a top secret mission to kill one of Hitler's key right hand men, Nazi SS General Reinhard Heydrich, the brutal Nazi "protector" of Czechoslovakia and an architect of the Holocaust.
And now a blockbuster movie, Anthropoid, being launched in Britain on Friday is to tell the story of their heroic and ultimately tragic exploits.
The Shropshire back-story has led an author and historian to campaign for some sort of memorial plaque in honour of the heroic pair in the village of Ightfield, near Whitchurch.
John Martin researched Operation Anthropoid, as the mission was called, for a book, including that close friendship that developed between two soldiers far from home and the two young sisters in the village.
"My campaign for a historical plaque in Ightfield has so far been unsuccessful but I certainly haven't given up hope," said John.
"The new movie, called Anthropoid, tells the story of these two brave soldiers and their heroic mission. I have had a small input, both in supplying historical information and even being invited to be an extra. It was filmed in Prague."
The movie stars Cillian Murphy as Gabcik, and Jamie Dornan as Kubis. The Shropshire sisters and their role do not feature, but author John appears in the credits as "Man at Assassination".
Kubis and Gabcik fled to Britain after the German invasion of their homeland, and while stationed in the grounds of Cholmondeley Castle on the Shropshire border in 1940 they became friendly with the Ellison family in nearby Ightfield.
"The Ellison family had two teenage daughters living at home, Edna and Lorna. The parents were Albert and Jessie," said John who, as part of his researches, interviewed and befriended the late Lorna.
In his book, she described their first meeting with the soldiers: "My elder sister Edna and I had been to the cinema in Whitchurch. In those days, especially with the war being on, there wasn't much else to do.
"We passed a soldier in uniform who was also waiting for a bus to take him back to Cholmondeley Castle. He asked to meet us tomorrow and we agreed.
"The next day we went to a cafe that sold tea in Whitchurch and met the soldier. His name was Jan Kubis. The next time we agreed to meet, mum came with us and this time mum invited him to our home, Sunnyside Cottage in Ightfield.
"As we all got off the bus in our home village of Ightfield a strange thing happened. There were two white gates to our garden and Jan Kubis suddenly stopped. 'It is just like home,' he said, and had to fight back the tears.
"After that Jan Kubis became a very regular visitor to our home and after a few weeks mum asked him to bring a friend if he wanted to as well as himself. He brought Josef Gabcik, who was from Slovakia."
The soldiers developed a close friendship with the family, staying with them while on leave or at weekends, and remained in touch after they left the area – and began specialist training for their mission.
Lorna's daughter Diana Hilson said: "There weren't a lot of young men around because they'd all gone to war. A man in uniform really stood out.
"My mum was very beautiful too with thick, black curly hair. She said the boys were very polite and kind but had a twinkle in their eyes."
Lorna was 15, but with Edna being 17 it seems her relationship with Jan was a bit more serious.
Diana, from Romford, Essex, said: "They had a bit more going on, those two. Jan gave Edna a ring. Now what this ring meant or what happened to it, I'm not certain. But it could have been an engagement ring."
They never told the Ellison family of their secret orders to assassinate Heydrich, only that they were being flown back to their homeland to help the Resistance.
John said: "Lorna described the last meeting as very tearful and Jan Kubis reminded the Ellison family of a promise he and Josef Gabcik had made, that once the war was over Jan and Josef would take the Ellison family to Prague to show them just how beautiful it was.
"Clearly, the men were planning on returning to Ightfield and the Ellison family as they left uniforms and personal items in the wardrobe – items that were eventually taken by the Army after the end of the war."
The pair were parachuted into Czechoslovakia in December 1941 and the climax came in Prague in May 1942 when they ambushed Heydrich's open-topped car.
Heydrich was injured but survived, and at first it seemed the mission had failed, but days later his condition deteriorated and he died.
The Nazi retribution was terrible. In the village of Lezaky, all men and women were killed. In the village of Lidice, all the men were murdered and the village was razed to the ground. Some estimates say that about 5,000 in all died in reprisals.
A huge reward was offered for information about the attack team. They were betrayed for the money and, holed up in a Prague church, the seven of them held off SS troops, but all died, either in the firefight or by committing suicide.
Kubis was mortally wounded and died in hospital and Gabcik was one of the last four who staged a desperate last stand in the crypt, during which they made an attempt to tunnel to safety. They shot themselves when their ammunition was nearly exhausted.