As does much of Paulsen's fiction for young adults, The Crossing features a young, male protagonist who forms an unlikely bond with an adult male deeply and adversely affected by war.

Highlighting their interdependence, this relationship finally helps both characters to be physically or emotionally free. Other recurring themes in Paulsen's fiction are physical survival, respect for the natural world, humanity, individuality, and acceptance of death.

The fast-paced action-adventure aspect of the story is tempered by a third-person narrative which reveals Manny's and Robert's thoughts and feelings throughout. Violence, destruction, and man's capacity for inhumanity are portrayed as reflections of the "real" world, ever at odds with the characters' instinct for what could be: a serene, harmonious existence from cradle to grave.

In their separate lives, neither Manny nor Robert knows serenity. This does not prevent either, though, from dreaming of, or wanting, that...