Magic Guardians

In Magic Guardians, the sequel to Magic Thieves, Rita is back home from her adventures in Terra, a land where everything depends on magic for survival, even the plants and insects. But then friends from Terra visit and tell her that the level of magic there has decreased so much that patches of death are developing all over the world. And people are succumbing to a mysterious magic sickness. Rita feels she must return to Terra, so she can use her special gift of magic sight to help repair the magic system. But first she will need the cooperation of the wizards. And she isn't likely to get that, since they think she is the cause of the disaster.