The Forbidden Tower tells the tale of the initial bonding of the foursome who broke new ground by defying the planet's laws and the will of the Comyn--the powerful race of psi-gifted people who are run the planet.
The deepening relationships between members of the foursome, contrasted with the growing conflicts between them and those who oppose the 'Forbidden Tower' they've built in the overworld, lead to a rich and gripping story.
The subplot of Callista's struggle to break the rigid taboos imposed upon her as a 'Keeper' so that she can be a true wife to Andrew and follow her own desires, is dramatic and fascinating.
This is a novel with many complex themes interwoven into a rich, fascinating story. I enjoyed each element of the many plots, and thoroughly enjoyed it.