Leonardo and the Death Machine. Robert J. Harris

up to three storeys high, with balconies jutting out of the top floors. Neighbours on opposite sides of the street could almost reach across and shake hands with each other.

      As he approached the River Arno, Leonardo saw the flatboats heading downstream, carrying off their bolts of brightly coloured Florentine cloth to be transported to Spain, France, England and Germany. Other boats were bringing their cargo of untreated wool into the city to be washed, combed and dyed in the factories.

      The city’s oldest bridge, the Ponte Vecchio, loomed ahead, its honey-coloured stonework bathed in the glow of the hot August sunshine. Both sides of the bridge were lined with the shops of butchers, leatherworkers and blacksmiths. As Leonardo crossed over, a blacksmith tipped a bucket of ashes into the river, provoking a volley of curses from the boatmen passing below.

      As soon as he entered the Oltrarno, Leonardo was reminded of his home village of Anchiano, many miles to the north. Washing was strung between the trees, chickens scratched at the doorsteps, and everywhere there was the smell of garlic and baking bread.

      In stark contrast to the humble cottages was the huge stone palace Leonardo could see rearing up like a cliff face in the middle of the Oltrarno, with workers swarming all over its scaffolding. He knew from the gossip of his fellow apprentices that it belonged to Luca Pitti, an ageing politician who liked to think of himself as Florence’s leading citizen. Even though the real power in the city lay in the hands of the Medici family, Pitti was determined to prove that he was every bit their equal, even if he went bankrupt in the process.

      Leonardo turned right, away from the palace and towards the church of Santo Spirito. Silvestro’s workshop was in one of the alleys behind the church, but Leonardo wasn’t sure which one. He paused to sniff the air and immediately caught the pungent scent of cow dung, burnt ox-horn, and wet clay, all of which were used in the casting of bronze statues.

      Following his nose he soon arrived at the shabby workshop of Silvestro. The shutters hung drunkenly from the windows and there were several tiles missing from the roof. Acrid smoke streamed from Silvestro’s furnace and hung in a sullen, black cloud over the street. Finding the door ajar, Leonardo pushed it open and stepped inside.

      A pair of surly apprentices in stained, threadbare smocks looked up as he entered. They were mixing up a supply of casting wax. One had a face covered in pimples while the other was twitching as though his clothes were filled with lice.

      Proud of his own finery, Leonardo drew himself up in a dignified fashion and inquired, “Is Maestro Silvestro at home?”

      The two apprentices turned to each other with dull, expressionless eyes. Leonardo was reminded of a pair of oxen in a field.

      “He’s in his private studio,” grunted Pimple-face.

      “And where would that be?” asked Leonardo.

      The Twitcher tilted his head to indicate a stout door at the far end of the workshop.

      With a curt nod of thanks, Leonardo moved on. Behind him he heard one of them mutter, “He must think he’s an envoy from the Pope.” The other apprentice sniggered.

      Leonardo ignored them and cast his eyes over the room. The shelves along the wall held only a few jars of pigment and these were thickly caked with dust. Discarded bristles and splinters of wood littered the rush-covered floor.

      As he raised his fist to rap on Silvestro’s door, Leonardo was brought up short by a sudden outburst of angry voices from the room beyond. They were as furious as a couple of dogs fighting over a bone. Even muffled by the door their words were clearly audible.

      “Today! You said today!” snarled the first voice, rough as sandstone.

      “I said the components would be complete by today,” the second voice boomed like a gusty wind. “I never said the construction would be complete, never!”

      “I think you know what happens to men who cross me,” rasped the first man.

      “Save your threats for those you are paid to terrorise,” the second man said. “All will be ready on schedule.” Leonardo could hear the weakness underlying his confident words.

      “Very well,” the first voice grated. “But I will hold you to that at some cost if you should fail.”

      “Silvestro does not fail,” the other retorted with renewed bravado. “He is only let down by lesser men. Do not worry, we will bring destruction down on the plain, eh?”

      “Be sure of it,” was the brusque response.

      Leonardo had been leaning in closer and closer. When the door opened, his heart leapt into his mouth. He jumped aside as a fearsome individual in a dark green hood and cloak swept out of the room.

       3 THE INFERNAL DEVICE

      The stranger halted and fixed Leonardo with a hostile stare. The man’s sallow face was all sharp angles with heavy brows and a slash of a mouth – as if it had been carved from flint by an impatient sculptor and left unfinished.

      Leonardo felt himself being probed by the cold, grey eyes. He had the awful feeling that if the man suspected he had been listening at the door, his life would not be worth a single denaro.

      The stranger’s gaze moved down over Leonardo’s garb, his expensive tunic and scarlet hose. A flicker of amusement curled his lips. You are obviously no threat, that thin smile seemed to say. I don’t need to waste any time on you.

      Without speaking, he turned and walked away. Leonardo felt insulted and relieved at the same time. Taking advantage of the open door, he stepped cautiously into Maestro Silvestro’s chamber.

      The artist was standing at the far end of the room with his broad back to the doorway. He was grumbling angrily to himself as he poured a cup of wine. He tossed the drink back in one swift draught, like a man throwing water over a blazing fire, and immediately refilled his cup.

      “I’ll skewer him, that cut-throat, if he talks to me like that again,” Leonardo heard him growl.

      He paused inside the doorway, uncertain what to do next. See and understand, Maestro Andrea had told him. He studied the artist in silence. He noted that Silvestro’s once expensive clothes had been sewn up and patched many times over. That suggested he had once been a prosperous artist who had fallen on hard times. The fact that the clothes hung about his body in loose folds meant he had also grown thinner. Probably through guzzling jugs of wine in place of his meals, Leonardo guessed.

      He peered around as Silvestro continued to mutter bitterly into his cup. Immediately to his right stood the master’s desk, its surface cluttered with coloured vials, lengths of decorative framing, and jars of powder and ink. Leonardo’s eye was immediately drawn to a large sheet of paper that lay in the midst of the confusion. It was covered in drawings the like of which he had never seen before.

      He took a furtive step closer to the desk. The page was crammed with intricate diagrams of notched wheels, pulleys, rods and weights, all fitted together into a complex mechanism.

      Is this what the two men were arguing about? Leonardo wondered. And if so, what is it?

      He had seen arrangements of cogs before, in the watermill on his family property at Anchiano, but nothing quite like this. Once he had even seen something similar inside an expensive clock that Maestro Andrea was embellishing for one of his clients. But this device was not exactly like that either.

       What was it they had said about destruction?

      He peered intently at the diagram, trying to piece together in his mind what would be the consequence of the weights moving, of the cogs turning one against the other. With one finger he began to follow the lines, tracing out the possible movements of the device. He was so absorbed in his study he was taken completely by surprise when a beefy hand clamped on to his shoulder.

      “Who