Toby Lolness is just one and a half millimetres tall, and he's the most wanted person in his world, the great oak Tree. When Toby's father makes a ground-breaking discovery, tapping into the very heart of the Tree's energy, he also realises that exploiting it could do permanent damage to their world. Refusing to reveal the secret of his invention to an enraged community, the family is exiled. But one man is determined to get hold of the forbidden knowledge...and his plan is to destroy the Tree. Now Toby's parents have been imprisoned and sentenced to death. Only Toby has managed to escape, but for how long?