 Why is Trella being attacked?
Trella swung with her whole body, and slapped him so hard he nearly fell from his chair. The dark man, who had grabbed Trella's arm, released her and ran for the door. The ship that they boarded on Moon Nine was one of the newer ships that could attain a hundred-mile-per-second velocity and take a hyperbolic path to Earth, but it would still require fifty-four days to make the trip. She told him only that she was a messenger, sent out to Ganymede to pick up some important papers and take them back to Earth. When it was found at last, he sent Trella, his most trusted secretary, to Ganymede to bring back to him the notebooks found there.
 The author does not give a clear reason for the attackers' motivations
 The author does not give a clear reason for the attackers' motivations  The attackers wish to steal Trella's documents  The attackers wish to violate Trella  The attackers are sent from Dr. Blessing to test Trella's loyalty