This book is the darkest of the first five, and deals with the heavily emotional issues of puberty and the impending death of a close family member. At the outset of the book Nita (Juanita) Callahan and Kit (Christopher) Rodriguez argue about the best way to clean up a waterway. The argument seems petty because both are after the same goal. However, there seems to be a communication gap between the two.
This event sends Nita on a voyage of personal discovery that intensifies when she learns that her mother has cancer. For the first time since becoming a wizard Nita learns that even wizardry has limitations. Even Dairine, her powerful and talented younger sister, is incapable of handling the cancer that is slowly taking their mother. Dairine is justifiably angry at her own inability to kill the cancer, and realizes that to battle this demon will require a finesse that she does not possess.
Nita must go on a voyage of self-improvement that only she can undertake. She must learn to recognize and find the kernel of a being, be it a world or a person. Nita must learn to manipulate that core, to help it marshal the powers that the kernel represents and commands. Only by manipulating the kernel does Nita have a chance to save her mother from cancer.
As the book develops Nita finds friends from other planets who have been manipulating kernels for some time. Nita is also developing advanced skills as a wizard, and I can see the potential for Nita to advance in the wizard hierarchy. Eventually Nita comes to realize that even with all she knows and with all her will that she still needs the help of friends, who come through for her when she really needs it.
I was quite surprised at the dark atmosphere of this book. I wondered whether Diane Duane was calling on personal experience, battling a disease that we have so little understanding of in the only way she knows how. It seemed to me that Diane caught a feeling, an emotion, quite well, which also made me wonder at the appropriate age range for this book. I would recommend perhaps ages 12 and above, or perhaps even a bit more.
In spite of the dark atmosphere, I enjoyed this book and would rank it as perhaps the second best book in the series after "A Wizard Abroad." Because of how well Diane created the imagery of the fight with the cancer and Nita's battles with the Lone Power I give this book a solid five stars.
This story stands reasonably well by itself. However, I recommend reading at least the first story in the series, "So You Want to Be a Wizard," and preferably the second story, "Deep Wizardry," prior to reading this book. Reading the third book in the series, "High Wizardry," adds little background information other than reinforcing the relationship between Nita and Kit. The fourth book in the series, "A Wizard Abroad," I would also recommend reading because this book furthers the emotional conflicts within Nita as she continues to mature into a young woman.