Now that Maeve Merritt has surrendered Mermeros, the djinni she found in a sardine can, she expects her life will be dull as dirt. Mermeros, however, has other plans. Maeve's friend Tommy, the former orphan, has been adopted by Mermeros's newest owner. When Tommy's father tries to use one of his wishes, he and Mermeros go missing--and without a guardian, Tommy will be forced back to the orphanage. Maeve, Tommy, and their best friend Alice embark on an adventure full of magic and danger to rescue Tommy's father and the djinni they've grown to love.