Four children temporarily lose their parents just as they are about to begin the race that offers their last chance of escaping poverty. Their task is to map a rail route through an uncharted wilderness.

They overcome the many obstacles posed by nature-bears, bees, bats, river crossings, cliff falls, impossible weather-but can they survive the treachery of their competitors?

This is a fast-paced and charming novel. Its children are brave and competent but not always right. Its world is magical enough to be intriguing but close enough to our own to keep the reader on firm ground.