Derrick's family was enjoying the holiday - after the initial shock of seeing 'Derrick' naked and partly minotaur the first day, they had loosened up themselves. Ironically, they had explored many forms and other changes while the boy they thought was their son got more bullish, then changed back to human every day. After a week, the others simply criticized him for not trying other shapes. Better yet, the real Derrick had adapted to his new form as a homely ginger worker, and had not left the Spa stables once. Thanks to the faun's adjustments and continuous exposure to further spells, the former son and brother was not only happy mucking stalls and grooming animals, he was becoming incapable of doing anything else.
Grug/Derrick was clomping on hooves, about halfway changed back to a minotaur when he made his nightly trip back to the bar. The faun was ready, and reversed the bullish transformation so that Grug/Derrick was fully human again. After wiggling his toes, the boy sighed. "Too bad I keep reverting."
The faun chuckled. "That's been what saves you! If you change from being the boy, the whole spell is likely to fall apart and you'll lose the chance to stay human." He waggled his eyebrows. "But... I did some checking and you can make some changes that won't jeopardize the switch. In fact, there is one that would keep you fully human right up to time to leave, and might even help you with passing as Derrick once you get 'home.'
"Really?" Grug/Derrick was immediately interested. "What have you got in mind?"
"Age is about the only thing you can work with and keep the switch safe. You can age up some, though that would not be much different. And the minotaur changes will still keep going." The faun grinned. "But, you could get younger. And if you spent this last week in the nursery, the magic there would keep you a human infant!"
Grug/Derrick frowned. "Baby bottles and diapers for a week? Not my idea of fun."
The faun shrugged. "You want to try some magic, you can get older or younger and still keep your freedom, but the minotaur changes will keep going. And don't forget that if you went for infancy, they offer full mental adjustment so being a baby would be normal."
"I guess that would make the last week go fast." Grug/Derrick thought about it. "I've made a couple of minor slips, but so far Mom, Dad, and Julie haven't been paying a lot of attention. If I was in a nursery, they wouldn't expect anything at all. But how does getting younger help me if I make the exchange?"
"One of the nymphs heard the parents talking about the boy not doing well in school. It probably wouldn't be that hard to get them interested in not returning a child Derrick all the way back to his high school age." The faun grinned. "You know how it works. Drop a few hints that Derrick could go home ready to start first grade, of course 'not something we would normally do, but this is such a special case, and if you REALLY want to have your little boy start school again with most of his 15 year-old knowledge and be a prodigy..." He batted his eyelashes.
Grug/Derrick laughed. "Oh, wow! Have the parents asking for special favors? That's perfect!"
The faun nodded. "If you happen to slip up once you are there, well, of course little Derrick is confused - he's ten years younger!"
Grug/Derrick looked at his now fully human reflection in the mirror. "Any change other than minotaur would make the family happy, I think. And I really like the idea of going home younger. Go ahead and work that idea. As for me, I think I'll..."