The Last Zoo — Samuel Gayton

Pia lives in a zoo in the middle of the Pacific Ocean with her parents (both ghosts), several old and cranky genies, a devil, and two young angels. She spends her days trimming genie-beards, trying to avoid being tricked into selling her soul, and waiting for the angels to make a miracle big enough to save the world. Then the angels go missing. Can she solve the riddles of the mysterious haloes the angels have left behind? Is the zoo's devil really trying to help her? And what does this all have to do with her best friends, the Rekkers? Pia needs to solve the mystery fast, because everything around her seems to be ending: her friendships, her childhood, and maybe even the world itself.