After escaping from their comfortable classroom cage, two rat brothers journey around the world, caught up in a plot to steal a jeweled statue—the fabled Burmese Bandicoot—and to exterminate humankind. More adventure than mystery, this is an inviting introduction to what promises to be a series starring courageous Frederick and comfort-loving Ishbu. Cox returns to the idea of rats as classroom pets she introduced in Third Grade Pet (1998), with these engaging explorers, personified but still representative of their species in appearance, skills and appetites. Frederick’s excellent education is nicely counterbalanced with Ishbu’s strong moral sense. Occasional classic quotations support the idea that, though caged, Frederick has paid attention in class. Small drawings of the rats introduce each short chapter. An endnote provides some facts about rats and bandicoots, as well as the Karni Mata Temple, the Fire Balloon Festival of Myanmar and the Australian Big Bird Race, all of which appear in the story. Fast-paced and suspenseful, this is solid entertainment for the middle-grade reader. (Fiction. 8-12)