In an unassuming town in the English countryside in 1943, a New Zealander quietly made history by becoming the first female commander of a British spy base.
Until now, she has remained unnoticed by history, flying under the radar for 76 years.
Today, British spy agency GCHQ released details of her work as part of commemorations of its 100-year anniversary.
Wellington-raised Pamela Pigeon, was the UK's highest-ranking female spy officer and commanded a unit of radio operators who formed a network which played a pivotal role in sinking the infamous German battleship Bismarck.
As a 6-year-old in 1924, she won a prize at a costume ball for her outfit as an "old English lady dressed in pink and white"; 19 years later she was the commander of a critical spy base tracking the movement of Nazi troops.
Few details are known about Pigeon's early life in New Zealand, nor about her life after the war.
Her father was a surgeon who immigrated to New Zealand in 1902. Pigeon, who was born in the UK, attended school at Wellington's Queen Margaret College where she won several awards for language and speech writing.
Those skills later came into use when she returned to England to assist in the war effort.
At only 25, she took command of a top-secret team of linguists who listened in on shortwave German naval and air force radio.
As a target for German air force bombers, the operation was run out of a series of unremarkable wooden huts scattered across the remote countryside at Marston Montgomery, Derbyshire.
Radio operators would observe the unique "fingerprint" of enemy radios, then once identified intelligence officers could immediately distinguish between a bomber squadron or a fighter aircraft approaching without having to decode any messages.
"Staff would be listening to at least 25 different operators each, identifying individual radio signals – for example by the speed that people would type our Morse code. Once enemy operators were identified, this information could be used to piece together troop movements," the GCHQ says.
It was this network of radio operators who located, and enabled the sinking of, the largest German battleship ever built.
The Bismarck had been damaged in a naval battle and was trying to get to a port in occupied France, but it made a radio transmission that was intercepted, enabling the Royal Navy to locate exactly where the vulnerable battleship was located and ensure it was sunk.
Some of the Commonwealth's finest minds were recruited to help the British war machine break Nazi codes generated by the German's U-Boat-cloaking Enigma machines.
The most-famous codecracking operation was at Bletchley Park country estate, the top-secret operation led by Alan Turing immortalised in The Imitation Game, a 2014 blockbuster movie starring Benedict Cumberbatch and Keira Knightley, where Britain's finest minds strove to crack codes generated by the German's U-Boat-cloaking Enigma machines.
The code breaking work by the "unsung heroes" like Pigeon was "absolutely vital" in winning the war, Kiwi military historian Ian McGibbon says, especially in the crucial battle for the Atlantic.
"If the Germans had managed to sever that route from America to Britain, Britain's chances for survival would've been very poor," McGibbon says.
"Managing to defeat the German submarine threat, and affect operations in the western [Africa] desert, mainly through code breaking and radio fingerprinting, was absolutely critical. We're all lucky that the British were able to organise those efforts so effectively."
Pigeon was doing work similar in the UK to what some New Zealand women were doing at the top of the South Island with radio fingerprinting Japanese submarines.
They were all sworn to secrecy and many carried that oath to their graves.
"Pamela Pigeon was really part of a massive effort way behind the scenes that really gave the Allies a big advantage," McGibbon says, who said that while the UK spy agency's latest release of secret wartime sites after all these years is intriguing, it's long overdue.
"It's a whole other level of the Second World War that people, for many decades, had no inkling of – it's only more recently that it's come to light and we're learning a lot more."
War historian Christopher Pugsley agrees, saying that Pigeon is the latest unsung Kiwi hero to emerge from the Second World War. The skilled-linguist follows in the same vein as the New Zealander who orchestrated the mass airlift after the Soviets blockaded Berlin, Pugsley says, along with the two New Zealand railway companies that continued the train line through Egypt and into Libya to enable Field Marshal Bernard Montgomery's Eighth Army advance after the Battle of El Alamein.
"These people had a particular skill and did it so well. It shows how effective the total mobilisation effort was in putting square pegs into square holes and how after the war, where they had their whole lives still ahead of them, they just had to get on with it.
GCHQ director Jeremy Fleming said in the past century GCHQ had saved countless lives, but the nature of the work meant key figures of history often went unnoticed.
"Organisations like ours that seek to keep the country safe cannot shout about our mission," he said.
"From a quiet farm house in Kent to a discreet office block in Mayfair, our 100-year history is full of ordinary people working together to solve extraordinary problems."
This is how history's first female spy commander flew under the radar for 76 years.
Even Pigeon herself may have been unaware of the importance of her role, as radio operators were unlikely to have been told about their achievements.
The last public mention of her is as one of many New Zealanders who attended a meeting between Dunedin's former mayor and King George VI at a garden party at Buckingham Palace in 1947.