This novel for young people is the story of David, who is allowed to escape from a Nazi concentration camp and makes his way across Europe to a new home in Denmark. As the narrative details his struggles to survive and retain his sense of individuality, the narrative also explores issues relating to the nature and value of freedom and the power of faith.

The story begins with twelve year old David's escape from the concentration camp, an escape motivated and assisted by a character referred to only as "the man." He tells David how to watch for the right time to make his move, where to find some supplies in the nearby woods, and that he must eventually make his way to Denmark. David, not sure that the man can be trusted, nevertheless takes him at his word, and as a result gets away from the concentration camp and starts on his long journey. Along the way, he is helped by several friendly travelers, and by what he believes to be the spirit of his friend Johannes, who guided him through the early years of his life in the camp. Narration reveals that after Johannes died, David resolved never to care for anyone again.

Traveling by night and resting by day, David finds his way to a small town in Italy, where he finds himself a hiding place that quickly becomes a sort of temporary home. During his investigations of the town, he finds himself drawn to the church, which inspires him with its beauty but which he is afraid to enter. He is also inspired to pray for the first time in his life. One night, however, he overhears some of the people of the town talking about him and, fearful that they will turn him over to "them" (the Nazis who ran the concentration camp) David flees. As he continues making his way north towards Denmark, he encounters more friendly travelers, some of whom comment on his unusual ability with languages (which narration reveals he acquired while in the camp), on his watchful eyes, and on his apparent inability to smile.

At one point on his journey through Italy, David saves the life of a beautiful young girl, Maria. In gratitude, her parents take him into their home, and for a while, he enjoys good food, the opportunity to read, nice clothes, and a comfortable bed. However, after overhearing Maria's parents express their concerns to each other about how strange he seems, David again fears that he will be returned to the Nazis and flees.

David makes his way from Italy into Switzerland, drawing closer and closer to Denmark. He continues to get rides from friendly travelers and continues to develop his prayerful relationship with God, always ending his prayers with the declaration "I am David." While traveling through Switzerland, he meets a woman named Sophie, who befriends him and tells him a story of a woman from Denmark whom David quickly becomes convinced is his mother. Determined to find her, he leaves the comfort and safety of Sophie's home and continues his journey, but the bad weather of the approaching winter wears him down to the point of near collapse. He is taken in by a farmer and his family, all of them treating him like a slave over the winter and planning to take him to the police in the spring. During this time, however, David makes friends with the farmer's dog, King, who follows him when he eventually escapes.

At one point in their journey, David and King accidentally encounter a group of "them" manning an outpost. Fearful of capture but aware that his only option is to run, David is paralyzed with indecision, but King rushes out from their hiding place and distracts the guards, sacrificing his life so that David can get away. Traveling without his friend makes David lonely, but he is more determined than ever to reach his goal, and eventually makes his way to Copenhagen, the capital of Denmark where, at the point of exhaustion, he is reunited with his mother.