This is the final installment of Maurice Gee's O trilogy, which began with The Halfmen of O and continued with Priests of Ferris, which together make up what is perhaps New Zealand's most famous and beloved fantasy saga. Centered on Susan Ferris and her cousin Nick Quinn, the books recount their activities on the planet O, a beautiful but brutal world upon which the internal forces of good and evil are forever at war within its inhabitants. In the first book, Susan managed to restore the balance by returning two Halves of good and evil to the Motherstone, giving what had previously been Halfmen to choose between darkness and light, only to return in book two (a year later for her, but chronologically one hundred years in O) to find that humans had predominantly strayed toward evil once again. Even worse, these evil-doers had created a cult in her name, and calling themselves the Priests of Ferris, used her legacy as a tool for cruelty and control.
"Motherstone" begins directly after the conclusion of "The Priests of Ferris" (making it more of a direct sequel than "Priests" was to "Halfmen") as Susan and Nick attempt to return to Earth after successfully tearing down the sect of priests. But their mission on O is not yet finished, as remnants of the priesthood remain, and one of them has a plan to dominant O once and for all. The mad-priest Osro manages to ambush Susan and Nick at the mine that serves as a gateway between the two worlds, and takes them hostage. As the cousins soon discover, the ex-priest has created a terrible doomsday weapon that could not only enslave the people of O, but destroy the planet itself - particularly if the Freemen retaliate by building their own weapon.
The first half of the book is quite intimate in detail, as first Nick, and then Susan attempt to escape from their captors and gather information that can help them defeat this latest threat against O. Gee creates some riveting chapters as the two cousins separately traverse the land of O, eluding their captors and avoiding the dangers that the strange world offers. In the second half, the book takes on a more epic quality, as the cousins reunite with their allies, gain information from the legendary Freeman Wells, and formulate a secret plan that can save O once and for all. This plan (don't worry, I won't give it away) is quite shocking in its extremity, and my feelings on it are a little mixed, particularly since one cannot help but compare the state of O with our own world. Debating whether the solution is justified, or whether it's an optimistic or hopelessly pessimistic outcome are questions that linger long after the book has been put back on the shelf.
Likewise, the story has several key issues that have immediate parallels with the real world; in the last book it was the corruption of religion into something cruel and dangerous, here it is the use of weapons and humanity's tendency to build more to defend oneself rather than disarming all of them. It is a difficult conundrum, but the humans of O and their flat refusal to give up their warfare provides justification for the extreme measures that Susan and her allies take to restore O for the final time. There is a sobering discourse on human evolution and "the swamp beast" that lingers on in human minds throughout O that demands comparison with our own world, particularly in Susan's growing despair that no matter how many times she attempts to save O from itself, it always slips back into violence and war. If there's no hope for O, is there any hope for us?
Those who have read the previous books will find most of their favourite characters return for one last go of it: Susan and Nick of course (who has a *much* bigger role to play this time around, particularly in the final chapters), Dawn and Soona, Jimmy Jaspers and his bear-companion Ben, and individuals from the races of the Bird, Stone and Seafolk. Everyone has an important part to play, and like any good ending to a story, the conclusion leaves us with a sense of loss, change, growth and bittersweetness.
The O trilogy is a great series, by a well-loved New Zealand author - practically every schoolchild in New Zealand will read these books sooner or later (I suppose it is what The Chronicles of Narnia are to the Brits, and the Oz books are to the Americans), as there is a great sense that these are kiwi kids dealing with a world that bears a striking resemblance to the New Zealand countryside. As such, they are an invaluable part of our children's literary canon.