This is book number 6 in the Young Wizards Series series.
While Nita grieves over her mother's death, Kit tackles a challenge as dangerous as it is strange: Rescue a young wizard who has vanished on his first assignment. This new wizard is unlike any other--he's autistic and he's a magical prodigy. His power is enormous. Now Kit and his dog, Ponch, must track down the missing boy before the Lone Power finds him.
"A fine fantasy. . . . Beautifully and fully imagined."--Booklist