The events of Passager take place in a forest in Britain in the late fifth or early sixth century, the era when the Romanized Britons were being pushed out of their lands by the Angles, Saxons, and other Germanic peoples. The focus in Passager is very much on the life of a small boy abandoned in the woods, with the larger issues only hinted at in Merlin's prophetic dreams.

The action first takes place among the oak trees of the forest, with the boy encountering meadows and streams and having to beware of predators, especially wild dogs that hunt him and sometimes force him to flee into the upper branches of trees. His experiences make him an expert at holding so still that he seems to become invisible, thus confusing predators, and his need for food has led to his discovering what the forest has to offer in...