"For someone who's just had a symbiot implanted."
"A what?" squeaked Jon.
"A symbiot," answered his mom. "You know, two organisms living together for mutual benefit. I'm sure you kids have your own names for it. I'll admit that I'm not sure why you wanted to do this, but if you say its for school..."
"Yeah, Mom," Jon answered, lamely. "Its for school. Pretty important, too."
"If you say so," said his mom. "You might want to get some rest, Jon. The doctor said the sickness will go away in a few days, but its not going to be pleasant until you're body and the symbiot get used to each other."
"All right," said Jon, backing towards the stairs. "I'll do that." Running upstairs, Jon found the wishing rock. Did I have something replaced? he thought. Or did I have something added? He wished to know what had happened. The stone flashed, giving Jon the knowledge he wanted.