Derrick gaped at his new reflection, torn between anger and amazement. His fingers reported that it was all real, and as he watched, he could see his hair slowly becoming redder and coarser. "How much am I gonna adjust?" His voice cracked with nervousness.
The girl smiled as she tousled his hair again. "That depends on how willing you are to accept this. If you cooperate fully, I can make some... improvements as a reward. After all, you are helping out the other boy."
"What kind of improvements?" Derrick was still staring in the mirror, his hair lengthening into an unkempt reddish tangle.
"Oh, the kind most boys want." She reached down and he gasped as she smeared some kind of warm cream over his genitals. "And a few to make you happy with your lot in life." Her other hand stroked his forehead.
Derrick shifted his legs as pressure built and he could feel his cock swell. But he kept staring in the mirror as something changed in his expression, in his eyes. His features went slack, and he stared dully at the reflection, then his mouth opened in goofy grin. That was his face. He liked his face. Memories swirled in his head, and he felt odd sensations as muscles pulled and his body altered. He was strong, a good worker. He liked working, simple tasks that he did not have to think too much about. Thinking was hard. In the bed next to him, the new Derrick's body became athletic and trim, while his form got thicker, more mature, and more suited to common labor.
He heard the other boy sit up and looked over to see the face and body he had come in with. The handsome youth grinned back at him and said "Man, I can't thank you enough. I'm gonna love being you." He looked at the girl. "And you are sure he's happy?"
She chuckled. "Oh, Randy is quite happy now, aren't you?"
Derrick sat up slowly, feeling a little confused, but grinned happily and nodded. "Yeah! I'm happy!" His words were bright and cheerful like those of a small child - even though he was now a hulking 19 year-old.
"Time to go back to work, Randy." The thick, muscular laborer who had been Derrick sat up and slid to the floor awkwardly in his usual clumsy way. "Go on back to farm. I'm sure they have missed having you there."