Suspicion

After escaping from the alien Aranimas, and subsequently the space station that rescued them, Derec and Katherine find themselves miraculously transported to Robot City. They used the Key to Perihelion, a device that somehow allowed them to travel instantly across the galaxy. I like this idea because it is twist on space travel that allows the authors to work out unique plot elements throughout the rest of the series. Derec and Katherine arrive to find themselves the only 2 suspects in the murder of a human in a city full of robots.