Ace and Crystal are invited to the Pleasure-Star, an exclusive space station resort connected to the Earth via an orbital elevator, Skystalk, for a vacation. Meanwhile, the station's owner, Anson Harshaw, is investigated by Dr. Wu for allegedly conducting illegal mind-transfer and cloning experiments. Crystal witnesses Dr. Wu being chased by androids, and orders Max to come and investigate. They are captured by Harshaw, and learn that he is replacing all the visitors to the Pleasure-Star with android duplicates in order to control key positions in the World Government. Max uses an escape pod and contacts Jake, who arrives to bail Ace and Crystal out of trouble. Harshaw decides to blow up the space station, leaving the rest of the connecting Skystalk to fall onto the Earth. With Ace and Crystal trapped inside the Skystalk itself, the other Centurions have to figure a way to rescue them and save the Earth from Skystalk's descent. Science Lesson: Gravity by Ace.