So I debated about posting this since I wrote it mostly for myself as an experiment, but I think it turned out alright so what the heck. Idea came from a book my friend gave me for Christmas that reveals Leonardo was responsible for deducing not only bloodflow but the valves in the heart and their function more or less. He did this by studying cadavers and spending a lot of time by the river, which he apparently loved. I've always thought that Leonardo being a great anatomist and having an assassin like Ezio as a friend was too perfect a pair to ignore-what's a better live specimen than a master athlete like Ezio? I decided to combine the ideas and use the Apple's ability of knowledge relay to write this.
To say he wasn't tempted to pick the apple up and study it for all it was worth was a lie. To say he was resisting that temptation well was also a lie, but he valued Ezio too much as a friend to betray him by taking something that wasn't his.
It had lingered in his thoughts though, ever since he first laid eyes and palm to it and now the gold called to him from its spot tucked safely under Ezio's things. Leo paced his workshop, thinking about the vast array of knowledge that must be contained in that single sphere until it near drove him mad. His curiosity was eating him alive, and the tension thrumming through him was so strong he knew he'd never sleep. It was very, very late and his candles were a mass of pathetic stumps. Even Ezio, who was hiding out for the night, had been asleep for at least four hours. He forced himself to stop pacing and think, bracing his hands against the polished grain of his workbench to center himself.
"You are being foolish," he told himself, pressing his palms harder into the wood. "There is nothing inside that apple that won't be discovered in time." Knowledge was too powerful and too dangerous to consume all at once, and he already felt honored that he'd been able to spend his life to that point studying the most fascinating and obscure scraps of knowledge their world seemed to offer. He sighed, realizing that no matter what he thought about or did the apple would not leave his mind. He gazed absently down at the sketches scattered under his hands, lost in thought until one he'd done just that morning caught his eye.
He'd been theorizing on the function of the strings and seals he'd found in a cadaver's heart and had scribbled his thoughts down on the drawing he'd done. Anatomy was one puzzle he had yet to fully crack and sketching always soothed him so he gathered up his things and considered going into his dissection room to continue with the corpse from earlier.
He went into the cabinet looking for more candles so he could see the finer details of what he was drawing, but there was only one left and would not provide enough light. An uncharacteristic surge of frustration went through him and he closed the cabinet too hard, causing more papers to flutter to the floor. He almost stormed away but the face laying near his boot gave him pause. A rough sketch of Ezio, his eyes twinkling mid story, was laying in the dust and when Leo stooped to pick it up he felt suddenly much more centered. He was letting the apple steal his peace and his contentment with the things he already had. He smiled back at the picture, setting it gently on the table where a slew of motion sketches were laying about. They were all from the same session—he'd been expecting a model that night and when the man hadn't shown Ezio had volunteered himself.
"Sure," he'd shrugged, brushing off the favor like it didn't mean the difference between Leonardo finishing an important commission. The assassin had obligingly held dubiously still while Leonardo did detailed drawings of his shoulders and back, and afterwards he'd run and climbed around the courtyard so Leonardo could watch him and sketch the power of his strides just for fun. He'd found it relaxing, and it had touched Leonardo that Ezio had taken a beautiful afternoon and chosen to spend it joking with Leo and acting as his muse.
"I don't think you understand what this meant to me," Leo had said, clasping Ezio's hand and smiling warmly. "Thank you, my friend."
"Of course. You have done more than enough for me, it was time I repaid you. Feel free to sketch me any time you like, just try not to get my bad side," he'd teased.
Standing there in his dim workshop, the apple tugging at his mind, Leonardo decided to take Ezio at his word. A few minutes later he was sitting in the side room where a couch was made up as a bed and Ezio was soundly asleep, most of his robes and all his armor discarded on the floor. The apple was swathed in his tunic, the barest hint of its edge peeking out from the floor.
Leo lit his last candle and settled himself on a stool. He let out a calming breath, allowing his mind fall into the easy peace it did when he just let the images flow. Setting tool to paper, he began to sketch the elegant lines forming Ezio's resting body. His mind wandered lazily and the tension drained from his muscles. Soon he was making lazy loops that turned into the branching of veins that stood out on the inside of Ezio's exposed forearm.
Leo tilted his head and envisioned the cords of tendon and muscle as they were inside the arm Ezio had dangling off the edge, wondering with some disappointment what those beautiful structures looked like within the warm safe house that was a living body. Dissecting corpses was exciting and fascinating, but always a little melancholy. Decay began too soon for Leonardo's liking, and he was certain that something was lost to the understanding of anatomy when the body had ceased to function, even if what was left was still warm.
Ezio, as he was right in that moment, was the best model Leonardo had ever had and yet he'd have to wait for the assassin's passing to understand him fully. The thought made Leonardo's heart pang and he pushed it away. He cared about Ezio too much, he could never dissect him even if an unfortunate turn provided the chance. He'd be too busy grieving his loss to find any pleasure in the potential knowledge.
The assassin shifted, turning over suddenly and Leo startled out of his morbid thoughts, fumbling his pencil. Muttering softly he got off the stool and patted around for it, struggling to see in the waning of his half-dead candle. He'd been drawing much longer than he thought. The lack of light combined with his lack of sleep and in his growing inability to find the pencil he accidentally put a hand straight into Ezio's stuff. The cold surface of the apple met his palm and immediately started glowing, projections shooting out in all directions. Leonardo startled back but the reaction was already done and the apple continued to glow, though its action this time seemed purely light and silence, rather than the surge of power he'd witnessed before.
His curiosity overwhelmed him and he pulled the apple from its nest, forgetting his pencil completely. He stood there for several heartbeats once he was certain Ezio was not going to wake and just looked at the thing in his hands. "What are your secrets?" he whispered to it, trying to understand why it had activated now of all times. He'd barely touched it. "What is it you want to show me?"
It was as if the apple was listening. Its glow suddenly spread, racing up his arms and burrowing warm into the fibers of his body. He startled but didn't fumble it, staring down at the brilliant sight now lacing his forearms. His veins were glowing. His veins were glowing and with every pounding heartbeat they surged near white before fading back to that captivating gold. He held the apple in one hand and raised the other, curling his fingers and turning his arm, awestruck as the shimmering revealed the shadows of tendons and ligaments moving with his commands. "Remarkable," he breathed, looking down at himself. Anywhere he had bare skin, which wasn't a lot, seemed to be effected. The glow wasn't quite strong enough through his clothing, but curiosity got the better of him and he quickly undid the ties of his doublet one handed, elated to see his theory correct when the bright glow centered in the mass of arteries and cardiac muscle in his chest showed itself. He held his breath and stared at his own chest for a long time, utterly mesmerized. He was watching his own heart beat, watching the iridescence of gold as it shimmered over his ribs.
He needed to sketch this, he needed a better look. The apple was allowing him to see his own heart but the angle was all wrong and he couldn't fully appreciate what it was doing, what the pulse cycle looked like, where it began where it went—his mind was a swarm of excited questions and he could do nothing to answer them without another host—
He looked up at Ezio, who must have been beyond tired because the hair trigger assassin was still out cold. Slowly, very slowly, Leonardo approached and gingerly placed the apple next to Ezio on the bed, trying one more mental command towards it just in case.
It worked. The apple continued to glow even out of his hand, and without touching Ezio the remarkable effect had transferred to him. Leo had fully intended to scramble for his pencil and begin sketching furiously, but what he saw awed him so much he just stood there and tried not to be overwhelmed while taking it in.
He was watching Ezio live, in the most intimate, inmost parts. He was witness to something no one had ever seen—the calm, healing, restful pulsations of a healthy heart. He was seeing life itself, not just the still mechanics that hosted it.
Slowly, he knelt at Ezio's side, eyes locked on the mass of gold muscle nestled deep inside Ezio's breast. It beat slow, at a tempo that would have had Leonardo worried if it hadn't been so clearly strong. Each surge sent out a wave of light that passed into the rest of his powerful body, racing along hidden tunnels to illuminate the structures they sustained. Muscles he'd sketched in action were now being fed and healed in inaction, only the smallest twitches of dreams disturbing them.
Through the expanse of capillaries and vessels in Ezio's lungs he could actually watch him breathe, not only see the result of it in the rise and fall of his chest. Looking even closer Leonardo could see that the gold was not opaque at all—rather if he wished he could see inside Ezio's beating heart. A brief run of pride surged through him when he saw his theory about the membranes in the arteries were correct.
Valves. They were valves, and the four chambers he'd mapped so painstakingly onto parchment worked in a patient sequence along with the valves to make the whole thing run. He watched the flashing of those valves opening and closing, opening and closing as Ezio's heart continued its tireless work. Seeing with what power the heart beat even at rest, Leonardo marveled that it continued as long as it did.
He took a moment to blink away unbidden tears before he stooped to collect his pencil, feeling suddenly that he needed Ezio's permission to use him for something so intimate.
He'd sketched the cardiovascular system many times, but knowing the host was still alive made Leonardo feel like he needed an extra measure of reverence. Feeling guilty that he'd already used the apple without asking Ezio, he took it away and tucked it into the robes, the glow dying away and with it his moment of awe.
Ezio's body faded back to normal and he burrowed deeper into his blankets, muscles tensing in his side as he settled and his breathing deepened once more. Leonardo didn't feel he could ever really ask Ezio for something so personal so he resolved to keep the moment to himself, humbled to have been allowed to see something so magnificent. He resolved to write the proof of his findings down in his notes but leave out how he'd obtained the information. It was gracious enough for Ezio to offer himself as a model, Leonardo didn't feel comfortable asking him for anything more. At least not just yet.
"Thank you, my friend." He said quietly, feeling now that he could sleep. His mind was too full to be anxious and so he retired for the night with the last of his candle, pondering what he'd seen.