Cannot remember the name of this book! Help?

[musicalblonde7]

There is a book that was at a Scholastic Book Fair about 4 years previous, and I had read it. I cannot remember the name, or the entire plot, so I will write anything about it that comes to mind. If anybody has any ideas, PLEASE, tell me.

It was about a prince (I think his name was Christopher, but I cannot be sure), but he was lost when he was about 2 years old and he was taken in by someone in the forest. I think he had an interest in engineering and he liked to build. When he got older, he somehow had a penpal with a girl in the kingdom (it turned out she was a princess too). She had a spell cast on her by a witch that gave her the ability to read minds when she touched the person. At some point, she was in danger and he went to save her, and she almost died but he saved her, and some how her gift to read minds was gone. The family found out somehow that he was a prince too. He also built a bridge for the kingdom.