 Why is Jakdane going to Earth?
Trella feared she was in for trouble even before Motwick's head dropped forward on his arms in a drunken stupor. Perhaps she could call one of Motwick's friends; she had no one on Ganymede she could call a real friend herself. The dark man, who had grabbed Trella's arm, released her and ran for the door. The gravity of Ganymede was hardly more than that of Earth's moon, but the way the man picked up the limp Motwick with one hand and tossed him over a shoulder was startling: as though he lifted a feather pillow. “He and my mother lived on Jupiter until the oxygen equipment wore out at last. “If Dr. Mansard succeeded in landing on Jupiter, why didn't anyone ever hear from him again?” she demanded.
 Jakdane is the captain of the ship that Trella and Quest are taking to earth.
 Jakdane is a corporate spy from Moon 5 on a mission to infiltrate Dom Blessing's organization.  Jakdane is following Trella to Earth because he is stalking her.  Jakdane is transferring from his company's office on Ganymede to the corporate headquarters on Earth.  Jakdane is the captain of the ship that Trella and Quest are taking to earth.