Azalin's class go on a school trip to another planet. The planet Earth. Once on Earth, Azalin runs away. Her dream is to be a 'tronic when she grows up -- to be one of the special people who maintain the systems that keep the man-made planet of Newarth alive. But just before they left for Earth, she was told that Newarth already has all the 'tronics it needs. She will have to be a store-keeper instead. And she is to be 'sporting' about it. Azalin doesn't want to be a store-keeper. And she doesn't want to be sporting. So she runs away. She phones home to say that she'll come back when she's allowed to be a 'tronic. But life on Earth isn't as safe and ordered as life on Newarth. Alone on Earth, Azalin has no idea how much danger she's in. Especially when she wanders into the 'no-go' zone called 'The Rookery.' Even the Earth Police won't go there... Azalin comes down to Earth. But will she ever go back to home on Newarth?