The main character, Zeph, is a 15 year old living in a utopian society in the year 2870. In this distant future, all humans are absorbed completely by their own virtual realities. That is, except for all children under the age of 16. Those under the age of 16 are given the first 15 years of their life to develop their own identity and get an understanding of the world and how it works-- or at least how it used to work. They are taught strictly by AI, as all adults do not have any life outside of their virtual reality.
At the age of 15, all children are issued a MenteBox, which is a small cube that has the ability to access all corners of the human mind. Once they are issued their MenteBox, the children no longer must be taught. Instead, the information they need to learn can be uploaded directly into their mind. Also, the MenteBox is what allows humans to enter their virtual reality. All of the children impatiently await the day when they can enter their virtual reality for the rest of their lives.
Zeph was just like the rest of the children until he turned 15. Once he was 15, he was able to have a proper understanding of how the world worked until the MenteBox was created. The option of going into his own virtual reality until he dies is tempting, but he has formed several relationships with his friends in the real world and does not want to leave them. The story centers around his struggle of decision.