High Wizardry: Young Wizards Series, Book 3 (by Diane Duane)

Nita's younger sister Dairine takes center stage in this third Wizardry novel. Bratty Dairine, a computer whiz with smarts and curiosity, reads Nita's wizardry manual and plunges into taking the Oath herself. At the Museum of Natural History, a doorway is turned into a worldgate to outer space.

Before Nita and Kit can find her, Dairine's off on her own Ordeal to an alien planet in a faraway galaxy, having copied a double of herself and her computer. As Nita and Kit race to help her, she bumps up against yet another manifestation of the Lone Power. Danger escalates when It creeps into Dairine's mind, and she hasn't enough experience with spells to know how to combat It. Nita and Kit come to the rescue, only to discover that they've fallen into a trap set by their old archenemy, the Lone One itself.

Amusing aliens, glass turtles, and giant, slumbering computer chips populate this computer-driven science fiction novel that opens with a strong beginning, giving way to a meandering plot. Readers of the series have met the dauntless Dairine in the two previous Wizardry novels, and know her primarily as Nita's pesky little sister. This headstrong girl stumbles into wizardry, but goes through quite a transformation as a result of her experience with the Lone Power, emerging as a convincing heroine in her own right.

While Dairine's resourcefulness throughout is admirable, the plot sags into a quagmire of computerese. Unfortunately, much of this has the painful sound of someone trying very hard to sound computer literate. For kids who understand computers, some of this will be dated, and some downright incorrect. But for those who can follow it, the ending is worth the wait.