Wizard by John Varley
In this second book in the Gaia trilogy it is now many years after the Ringmaster first visited and Gaia has established a relationship with earth, joined the UN and allowed tourists to come and visit. She has also realized to protect her future she must make herself needed by earth and so she has begun offering miracles. Only 40 people per year are granted an audience with her, and those select few quickly learn that her miraculous cures to whatever ails them do not come without a price. Cirroco has found her long standing role as Wizard of Gaia to have its own heavy price that she did not fully understand when she accepted the job. We follow the adventures of two young pilgrims who come to Gaia seeking a cure for their diseases and soon find themselves trying to prove themselves on a grand adventure with Cirroco and Gaby trying to circumnavigate the ring of Gaia. The trip has a higher purpose than two pilgrims proving themselves. Not everyone will survive the experience, (though on Gaia that does not mean the end of their story) but those who do must face their own demons and learn to grow and change.
This is another gripping epic from Varley. Though in some ways very different than the first Gaia book, Titan, it nevertheless certainly has no trouble standing on its own as a great read.