Toby Lolness may be just one and a half millimeters tall, but he’s in big trouble.

His father, a brilliant scientist, has discovered an alarming truth about the great oak Tree that Toby’s people call home: it’s alive. And if they continue digging deeper into the heart of the Tree, their whole civilization could be at risk. In an attempt to silence Professor Lolness, the builders who control things in the Tree take him and his family captive. But Toby manages to escape, taking with him the secret to the Tree’s energy - a secret his pursuers will do anything to get their hands on, even if it means killing an innocent boy.