"Taller," Xan said, resting his palms and fingertips together. When Arnold's face responded by twisting ever so slightly with skepticism, an impish grin spread across the superior being's lips. "You look puzzled. Don't you believe me?"
"Not to be rude, sir," Arnold replied, pushing the rim of his glasses to the back of his nose, "but frankly, would YOU believe you?"
Xan stroked his chin thoughtfully and laughed, "I think I like you." With a simple gesture, Arnold's textbook snapped through the air and into Xan's hand. "Oh child, this material is beneath you," he said, browsing its pages with a disapproving shake of his head, "I can sense your intellect. Why do you fear failure? You hold yourself up to such an irregular standard."
Arnold blinked, his expression melting into an insulted smirk. "Child?" he scoffed, as if to point out Xan's own, even more youthful appearance, "What would you know about it?"
"Really? You're going to doubt the intuitive capability of a being who appears at will and can take your property through telekinesis? Even a boy as logical as you, witnessing what you've just witnessed, must realize there's more to this earthly plane than meets the eye. I've demonstrated my power."
Arnold considered this for a moment and gave a stiff shrug. "Well, you do use big words..."
"I'll take that as a good enough compromise! Well then," Xan said, smiling triumphantly, "As I already said, friend, you have been chosen -- your days of meekness, at this very moment, end. The spindly wimp before me shall become a lordly stud. But! Surely, a lad as well-versed as yourself in history knows there is no such thing as a free lunch. I do have conditions. Fortunately for you, my condition is in a way another blessing. There's a boy who's humiliated you, dominated you publicly, made you retreat into your books and studying."
"Caleb," Arnold said, practically gritting his teeth.
"Right." Even then, Xan could sense Arnold's fury boiling, and he felt certain he'd chosen the right mark. "I want you to visit upon him twice the humiliation he's shown you, in whatever manner you see fit. Get creative with it. Have fun. I'll be watching."
"Wait a second!" Arnold exclaimed, his skepticism suddenly all but vanished as he entertained the possibility of revenge, "Why are you doing this?"
Xan laughed as he started to fade away, "Does it matter?" And with that, he was gone.
"Ah... My history book....."
As he stared into the vacant air, Arnold considered the possibility, as any logical person would, that what he'd just experienced was either a dream or hallucination. He was too timid to try drugs, so that wasn't it, and he wasn't particularly exhausted by stress. Was he dreaming, then? He felt conscious. Was there a gas leak somewhere? After a moment of pondering this, he began to feel a warmth filling him, accompanied by something else. He'd helped his uncle move once, and the day after his unused muscles felt like they were on fire. This was like that, except instead of that painful, half-paralyzed stiffness, he felt surprisingly good.
The top button on his black-and-white patterned shirt popped, causing Arnold to realize just how tight his clothes had become. Could the puckish creature's promise be real? Quickly, he moved to undo the rest of his buttons before his shirt was ruined, when to his amazement he spied something he never thought he'd see through the plain white undershirt beneath -- definition. What had been a boring plateau of pale skin now gave way to the early formations of what were undoubtedly very real pectoral muscles. "No way..." he gasped, running his fingers along the newly tightened abdominals forming before his eyes.
Arnold's typical height of 5'8" fostered an envy in him toward the much more admired and successful sports players in school. Not only was he suddenly among their stature, he was on the verge of surpassing the tallest of them! With a giddy laugh, he lifted up his shirt to witness first-hand the changes. His pressed khakis conformed to the bulging muscles in his thighs, and were certain to give if his growth continued. Nearing 7', the former nerd was, to say the least, as studly as Xan said he'd be. Arnold had always had bookish good looks, but for the first time in his youth, he could honestly say he was smoking hot!
"This is really me," Arnold mused aloud. Even his voice startled him, an octave deeper and full of something he'd sincerely lacked: confidence.
Xan's promise fulfilled, Arnold knew he had a responsibility of his own to follow through on. The next day at school could not come soon enough.
What happens next?