The Alan Turing
Want to come over to Manchester for a bit of live crypto stuff, the prize ceremony and an opportunity to meet the organisers?
"Come on!" said Mike. "Back to the tomb!" Mike and Ellie left the John Rylands Library and ran the short distance to the cathedral. Ellie glanced over her shoulder and saw Brother Aldred with Darcie and Donna racing behind them. "Hurry" she shouted to Mike.
They entered the Cathedral and ran down to the crypt only to see a familiar figure standing by Robert de Gresle's tomb. "Barquith!" exclaimed Ellie. "I guess we shouldn't be surprised to see you here!"
"Indeed not," said Barquith. "I've been interested in the Mediaeval Manuscript for a very long time." He looked up to see Brother Aldred and the twins entering the crypt. "Brother Aldred, I presume," said Barquith. "I think you owe us an explanation. Whose grave is this?"
Brother Aldred moved to the tomb. "It belongs to the de Gresle family. William de Gresle was a knight in Richard the Lionheart's army when Lionheart was fighting Saladin. William met with Saladin, without Lionheart's knowledge, and brought back secret mathematical knowledge. The mediaeval manuscript describes where William hid that knowledge."
"Inside his sword," said Ellie.
"William left his sword and the manuscript to his nephew, Robert de Gresle. This is Robert's grave," said Aldred as he gestured at the stone tomb. "Robert de Gresle spent most of his life as Lord of the Manor of Manchester and he never had time nor inclination to decipher the manuscript. His priest vowed that it must stay protected and founded a secret order to ensure that the manuscript would only be found be those who could be trusted with its secrets. We call them 'the rightful'. I am the last of the order."
Aldred continued, "The manuscript was first hidden inside Robert's tomb, but it wasn't an ideal place: too cold, too damp for an old manuscript. When the John Rylands Library was built, one of my predecessors decided that it would be the perfect hiding place. He made sure that there were just enough clues to enable the manuscript to be found when the time was right. It was he who carved the message into Robert's tomb and ensured Mrs Rylands' stained glass window contained the code."
Barquith spoke up. "I couldn't help but notice that one of your order went to a lot of trouble to stop Turing, Ventris and me getting hold of the manuscript."
"That was just after the Second World War: a very dangerous time," said Brother Aldred. "We don't know what mathematics William brought back. We didn't know if it could be used to upset the uneasy peace. You weren't 'the rightful'."
"Now I am getting old and I have no apprentice. It's time for someone to decipher the manuscript and find William's secret. I'd heard of you four," he said as he gestured to Mike, Ellie, Darcie and Donna. "But I wanted to test you all first; to convince myself that you were indeed the rightful ones. That's why I've been leading you on this chase."
"I think it's time to discover William's secret," said Barquith. He and Brother Aldred pushed the alabaster slab covering the top of the tomb. After much effort, they finally unsealed it, revealing a gruesome skeleton holding a sword on his chest. Brother Aldred reached in, as respectfully as he could, and removed the sword.
Mike and Ellie re-read the manuscript. "'Turn the orb three times widdershins'. What does that mean?" Ellie asked Brother Aldred.
"Have you ever wondered how you would say 'clockwise' or 'anticlockwise' before clocks were commonplace?" he replied. "Widdershins means anticlockwise."
Ellie turned the blue orb in the pommel three times anticlockwise and Mike tapped the blade. There was a rusty click, and the pommel sprung open to reveal a very small, very old, piece of parchment.
Barquith unfolded the parchment and squinted at it. "It's rather hard to read," he said. "It seems to be describing some revolutionary mathematics that had been developed at the court of Saladin during the 12th century. Around that time, mathematical scholars from the Islamic world were far, far ahead of mathematics in Western Europe. They were developing decimal notation for numbers, constructing proofs by induction, doing remarkable things with planar and spherical trigonometry. And this document is about square roots, and how to take square roots of negative numbers!"
Mike, Ellie, Darcie and Donna all looked at each other, disappointed. "Complex numbers, that's it?" said Ellie. "We already know everything about them!" said Darcie. "We're far smarter than you!" said Donna.
"No, no, no! This is fascinating!" said Barquith. "This means that complex numbers were invented—or were they discovered?—300 years earlier than previously thought. This is a hugely significant discovery!"
"After all that, I wanted something a bit more important to show for it," said Mike, somewhat downcast as he picked up William de Gresle's sword. He brushed the cobwebs and dust off the blade, revealing a set of archaic runes. "Maybe this sword is worth something?" he mused. "Ahem. I'll take that," said Barquith. "I think it will look rather splendid in the Manchester Museum." As Barquith tucked the sword and the manuscript away under his own brown suit, Brother Aldred glanced over with a knowing wink in his eye.