Key Out of Time is the final book in a series that began with The Time Traders and continued with Galactic Derelict and The Defiant Agents. Ross Murdock, the hero of Key Out of Time, is a character with whom most young adult readers will sympathize. As a teen-ager, Ross got into trouble with the law, and often felt that he did not fit in with others. Just when he has found a satisfying career with the Time Agents and a close friend in the person of his older partner, Gordon Ashe, Ross is stranded in time.
Adapting to change is a major challenge in people's lives; the manner in which Ross accepts responsibilities in his new world helps readers understand the rewards of doing so themselves.