 What is Dom Blessings's relationship to Dr. Mansard?
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. “If Dr. Mansard succeeded in landing on Jupiter, why didn't anyone ever hear from him again?” she demanded. Trella could get a cab from here, but the Stellar Hotel wasn't far. Trella had the desk clerk call a cab to deliver the unconscious Motwick to his home. For some reason she decided against telling him that the assignment on which she had come to the Jupiter system was to gather his own father's notebooks and take them back to Earth. Motwick was an irresponsible playboy whom Trella had known briefly on Earth, and Trella was glad to dispense with his company for the remaining three weeks before the spaceship blasted off. 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. Her employer had impressed upon her that her mission was confidential, but surely Dom Blessing could not object to Dr. Mansard's son knowing about it. All these things had happened before she was born, and she did not know what Dom Blessing's relation to Dr. Mansard had been, but it must have been very close. The principle was the same as that used in operation of remote control “hands” in atomic laboratories to handle hot material, and with the surgiscope very delicate operations could be performed at the cellular level. Dr. Mansard and his wife had disappeared into the turbulent atmosphere of Jupiter just after his invention of the surgiscope, and it had been developed by Dom Blessing. Through all these years since Dr. Mansard's disappearance, 55 Blessing had been searching the Jovian moons for a second, hidden laboratory of Dr. Mansard. When it was found at last, he sent Trella, his most trusted secretary, to Ganymede to bring back to him the notebooks found there. Blessing would, of course, be happy to learn that a son of Dr. Mansard lived, and would see that he received his rightful share of the inheritance. Because of this, Trella was tempted to tell Quest the good news herself; but she decided against it. It was Blessing's privilege to do this his own way, and he might not appreciate her meddling.
 Dom Blessing was Dr. Mansard's assistant.
 Dom Blessing was Dr. Mansard's assistant.  Dom Blessing was Dr. Mansard's business partner.  Dom Blessing was Dr. Mansard's employer.  Dom Blessing was Dr. Mansard's best friend.