Rob sat on the small log beside his campfire, staring blankly into the flames, his black bangs drooping over his forehead, almost into his eyes, as he went over everything again and again in his mind: finding the musty old book misplaced on a shelf of the school library; translating the strange Latin dialect; finally understanding, with disbelief, the contents of the book; then the frenzied arrangements for this solo weekend camping trip, away from school, from family, from everything.

Because Rob had to find out if it was true.

Suddenly, the little pot hanging over the fire was hissing and bubbling over. Rob, yanked out of his reverie, jumped up and grabbed the handle of the pot. He carefully moved it away from the flame and waited until it had stopped seething before pouring it into the small glass jar he had ready in his other hand. As the contents mixed, they phosphoresced a brilliant blue for a moment, but then amazingly turned completely clear.

Rob held the jar at arm's length and regarded it warily. This was it. If the book was right, this should work. Rob slowly brought the jar up to his nose, but he could smell nothing. The contents looked almost like water, except slightly more viscous when he shook it. He stood almost a minute staring into the mouth of the jar before suddenly throwing caution to the winds, tilting his head back, and pouring the liquid down his throat. He tossed the jar to the leaf-padded forest floor and wiped his mouth.

He felt nothing. He had tasted nothing.

"At least it wasn't toxic," he thought to himself as he knelt to arrange the fire to be safe for the night.

He still hadn't felt anything when he opened up his tent and slipped inside. He sat for a while on his open sleeping bag, trying to determine if anything, any part of him felt, well, funny. At all. But it didn't.

With a sigh and a shake of his head, he stripped off his shirt and tossed it aside. "Stupid waste of time," he muttered. He had stripped down to his boxers and was about to pull the sleeping bag closed and try to forget everything when he felt an odd tingling sensation at his groin.

Turning his small gas lantern up to full, he quickly pulled off his boxer shorts, but, to his relief or disappointment (he wasn't quite sure), everything looked normal. His soft cock drooped over his hairless balls. But the tingling sensation was spreading, crawling up his torso and down his legs as he splayed them wide, a slight tingling warmth running through his veins. Rob bit his lip and involuntarily craned his neck upwards as he felt the warmth creep up his chest and spill down his arms. Inevitably, the sensation rose up his neck and filled his head, making him shut his eyes in momentary dizziness.

And then it was gone.

The night air felt slightly chill against his bare skin.

Rob took a deep breath and exhaled slowly. Was it real after all? Had it worked? The book had been reassuring in its calm, confident competence, spelling out each ingredient and each step of the process in painstaking detail. But could any recipe for a "Changeling Tonic" be anything but a fake?

The only way to know was to try. And Rob knew exactly what to do. He'd known from the moment he translated the first paragraph of the book, long before he had any idea of the book's full potential, and long before he entertained even the remotest idea that the book's contents might be real. Reading the book had given him many ideas, but first, he had to try... this.

Taking another deep breath and closing his eyes, Rob leaned his head back and visualized what he wanted. It wasn't difficult. He'd been visualizing it constantly for almost two weeks. Suddenly, his position shifted, making him fall back on his elbows. He opened his eyes and stared at the ceiling of the tent for a moment, wondering if the sensations he was feeling were real or imagined. Then he looked down.

It was real. He had four legs.

Four legs.

Just below his crotch, where his original legs, smooth and pale in the bright light of the lantern, joined his body, a small section of torso continued to a second crotch, where his two new legs joined. And between them, another cock, just like his original, hanging soft over a second pair of hairless balls. But it wasn't soft for long.

Both of Rob's cocks slowly stiffened and grew as he stared at himself, doubly aroused at the sight of his daydream become reality. He could feel every part of all four of his legs, kissed by a soft breeze of night air; he could feel the smooth plastic floor of his tent under all four of his feet; he could feel the hot rush of blood to both of his rising members.

Moving slowly and carefully, as if a sudden movement might break the spell, he lifted his two original legs into the air. It was an odd sensation, lifting his feet in the air while sitting with two other feet planted firmly on the ground. He carefully set his original feet, now his front feet, down between his two new legs, which were now, he supposed, his hind ones. Cautiously, unused to his shifted center of gravity, he rolled forward onto all four of his knees. His front hardon bobbed between his legs; his rear hardon slapped up against his small section of underbelly, pushing into Rob's front balls that hung in front of it.

Still unsure, but steadied by his multiplicity of limbs, he rose to all four of his feet as he stepped out of his tent. He stood for a moment, centaur-like in the firelight, feeling the dried leaves on the ground beneath his four feet, letting the cool night breeze caress his new, transformed body, feeling it slip among his legs, teasing his turgid cocks, brushing over his tightening ballsacs.

It took a short while to learn how to walk, for his legs crowded close together, and sometimes his hind foot would kick a fore heel, or one of his fore heels would tread upon the toes behind it; but he soon worked out the rhythm, and walked slowly around his campsite, enjoying the feeling of his crowded thighs brushing up against one another, his four feet padding on the soft forest floor.

In very little time, his rear cock had lengthened so that it rudely shoved his front balls aside, and was about to peek out between his front legs; both of his hardons ached for release.

Rob walked quickly back into his tent, and tumbled awkwardly back into his original sitting position, letting his fore legs splay outside of his hind legs. Reaching down, he took one cock in each hand, and instantly moaned at the dual sensation. It was like jacking off two people at once, but they were both him.

He stroked his shafts slowly up and down, sometimes in rhythm, sometimes out of rhythm. His breathing grew heavy as he slowly increased his tempo.

Then on one stroke of his hind cock, his finger brushed up against the pucker of his fore anus, just below his fore balls. There was tingling sensation that made Rob gasp.

Now was the time to try it. Finally. Now.

His hands abandoned his cocks with some regret, and he hunted through the backpack lying beside his sleeping bag until he found the tube of lubricant that he had brought with him. Working quickly, he poured some into his hand and quickly coated his rear cock, simultaneously inserting a finger into his fore anus. Rob gasped again with anticipatory pleasure, and all four of his legs writhed involuntarily, dragging his four feet back and forth on the floor of the tent.

Carefully, maneuvering muscles still somewhat unfamiliar, Rob stretched his body and guided his rear cock into his fore anus, where it was greedily welcomed, sliding quickly in as Rob let his body relax. He sat still for a moment, marveling at the sensation of filling himself, before his fore cock, rubbing against his tight stomach that rose and fell with each rapid breath, demanded his attention.

Leaving one hand on the floor to support himself, he reached for his fore cock with the other, and slowly, learning how to use his new muscles as he went, began to gyrate on his rear cock. Fucking himself.

The sensations were incredible: his lithe body twisting; his four long, limber legs writhing and brushing up against one another; his four feet planted firmly, heavily on the floor, all twenty toes curling and uncurling; his fore cock in the slick embrace of his lubed hand; his hind cock, probing the depths of his hot passage, which clenched tightly around it; that same passage, feeling the fullness of his hot, huge hind cock, ever growing.

Rob wanted it to last forever... but eventually it was too much. A final shot of ecstasy ran through his hind cock, and he immediately hunched forward and clenched his fore anus tight around it. He was shooting within himself, filling himself with his own seed. His fore cock suddenly jumped in his still moving hand and was shooting as well, covering his chest and stomach with blast after blast of hot semen.

Rob fell back on his sleeping bag, exhausted, his hind legs stretched out flat on the floor, his fore legs still languidly flexed, knees in the air. Even in the let down from that multiplied orgasm, Rob was still pleasantly charged by the natural sensations of his extended body.

Soon, the cum on his chest was cooling and drying in the night air, so Rob reached for a towel to clean himself off, brushing off his chest and stomach and carefully cleaning his fore cock. He reached down to clean up some semen that had dribbled out of his fore anus around his hind cock, but he left his hind cock lodged there comfortably.

After turning down his lantern, he lay back again and pulled one side of the open sleeping bag over his body. As much of it as he could. Both of his hind feet and one of his fore feet stuck out from the bottom and side of the bag, but the night was not too cold. And as he nestled his head into his pillow and began to slowly drift off to a satisfied sleep, he wondered what he might try tomorrow....