Gary Paulsen Blue Light also published under the title The Transall Saga

'This must be a real place,' Mark whispered. 'But where is it? And how did I get here?'
Whatever it was, the blue light was the key.

Mark Harrison is a thirteen-year-old boy who enjoys solitude, nature, and solitude in nature. We first meet Mark as he is in the middle of a five-day solo hike across a New Mexico desert. This is the first time his parents have allowed him to do something like this, and he is enjoying it immensely. While camping at night, Mark is awakened by the light of a brilliant blue beam shining on the ground from some unknown point in the sky. By a fluke of bad luck, Mark stumbles into the beam and is instantaneously transported to a strange planet.

The planet is similar enough to earth that Mark can survive, but strange enough that he has to struggle to do so. His first few weeks there are consumed with finding food and searching for the blue light to take him back home. After a while, though, he discovers that he does not dislike this solitary life and relishes in the challenge of survival. Then he finds out that there are people inhabiting this strange world, and he sets out to find them.

He first finds a group of primitive jungle-dwelling people. He endears himself to them by saving the life of one of their people; he stays with them for a few days and is captured as a slave along with them when a superior tribe raids the village. He is made into a slave for the chief of the tribe, since he looks different from the others and therefore is deemed special. Though he resents being a slave, Mark finds that he is forming a bond with these people, especially with the chief's daughter. Through them, he learns what planet he is really on and how he might get home. But now his conflict is whether or not he wants to go home--he likes the primitive life. He is shocked when he finds out that there is another like him--one from earth who also came to the strange world by a beam of light. He is a great ruler on this planet, and fears that Mark will try to overthrow him. So he tries to kill Mark and all who are with him. Because Mark knows that he is endangering his tribe by staying, he has to find a way home.