A typical working day for Dutch translator Anne Lee might involve interpreting in a court case or deciphering contract papers.
So when some letters from the 18th century detailing the daring theft of pirate treasure crossed her desk, it was the job of a lifetime.
The documents told the story of two Welsh brothers who stole a cargo of coins, silver and other valuables from the ship they were working aboard as crew members.
They buried this treasure on a Caribbean island.
As the story unfolded, it started to bear an uncanny resemblance to the tale of Robert Louis Stevenson’s Treasure Island.
This true story has now been published in a book, Treasure Island: The Untold Story, by American author John Amrhein, who had been researching the two brothers and the Spanish galleon they were aboard.
Anne, of Pipers Hill Road, Kettering, was contacted in 2003 by the writer, who wanted her to translate the hand-written letters that had been held at the National Archief in the Netherlands.
It was painstaking work – the old documents had ink blotches, the writing was in an ornate, swirly font and the letters were from a time before the Dutch language had developed uniform spelling rules.
Anne said: “I found that I could transcribe the letters and then translate them, and I was amazed how the text opened up.
“It turned out the letters were correspondence between Dutch commanders based in the Caribbean.
“I was completely under the spell of these texts.
“It was so interesting and I worked very long hours on it because I absolutely loved it.
“It has been the most interesting job I have ever done.”
The letters revealed an account of a Spanish galleon which had been diverted from its course by a storm.
The two brothers, John and Owen Lloyd, one of whom had a wooden leg, were entrusted with rescuing the ship’s valuable load of cochineal (a highly-priced red dye), eight tons of silver pieces, chests of silverware, gold and other jewels.
The brothers decided to seize their chance and claim the treasure for themselves.
John Lloyd was captured, but Owen made it to the Caribbean, where he buried the loot on Norman Island in the British Virgin Islands. Owen was later caught and held in the fort on St Eustatius.
He was condemned to the gallows for theft.
But as Anne discovered from the documents, Owen bribed his guards to make his escape.
She said: “It was an amazing real-life story that was unravelling in front of my eyes.”
Author Mr Amrhein found there were links between Robert Louis Stevenson’s fictional Treasure Island and what really happened all those years ago.
The grandfather of Robert Louis Stevenson was buried on St Kitts, a neighbouring island to St Eustatius, and Robert had gone to visit him the year before he started writing Treasure Island.
It also transpired that Robert married a woman called Fanny Osbourne, a former lover of one of John Lloyd’s descendants.
Then there is John’s peg leg, suggesting he may have been the inspiration for the legendary character Long John Silver.
So what happened to the treasure?
Anne said: “Some of it they had to give to the crew to bribe them to go along with the theft.
“They buried the rest of it on the island, but it was discovered by the authorities when they found out about it.
“At first, the brothers were celebrated as heroes because the Spanish were hated.
“This happened after the English-Spanish war, and the Spanish had behaved in an awful way and robbed a lot of people of their money.
“In the end, they didn’t get away with much of the treasure, which their wives were not very happy about!”
She added: “It has been an absolutely fantastic job and one I’ll never forget.”
Treasure Island: The Untold Story by John Amrhein is available to buy on Amazon for £20.