Young Wizards is a series of books by Diane Duane in which teenage wizards fight against the Lone Power, which seeks to destroy the universe.
In the Young Wizards universe, magic exists, and across the wide span of the universe it works in cohabitation with science to make interstellar and intergalactic life possible. Its purpose is to combat the spread and progress of entropy: the long, slow death of the universe, which was put into motion by the Lone Power. Since this is a battle being fought against an entity which really doesn't exist inside time as we know it, it's a very long fight, and one that has the potential to make your head hurt if you think about it too hard.
On Earth, however, magic is not practiced in the open, cultural norms being what they are. So life for magic-users becomes an intricate dance of deception and caution, often intermingled with keeping the knowledge that the planet is not only not alone but something of a galactic backwater hidden from the general populace.
Young Wizards centers, at first, around two characters: Nita Callahan and Kit Rodriguez, who have both only recently become wizards (hence Young) and thus only recently aware of this world-behind-the-scenes. The series takes us on a delightful and quite possibly very-downer-at-times romp throughout the universe, which is somewhat complicated at times by the fact that the first and seventh books of the nine so far were written twenty years apart. Hence, cultural anachronisms may often abound, though Duane has said she is negotiating to be able to rewrite some bits of the early books to blunt the gap some.
Ponch, Kit's dog (though he's more than just a dog), is aware of the PPC and can be helpful to agents who go on missions in the Young Wizards canon.
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