 Why does Mr. Oyster want to hire Simon and Betty?
He looked over at Betty and said, almost as though reciting, "What I need is a vacation." "Providence," Simon told her whilst fiddling with the aspirin bottle, "will provide." Simon said unenthusiastically, "Good morning, Mr. Oyster." The client fussed himself with Betty's assistance into the seat, bug-eyed Simon, said finally, "You know my name, that's pretty good. It's my contention that within a century or so man will have solved the problems of immortality and eternal youth, and it's also my suspicion that he will eventually be able to travel in time. Simon seemed incapable of carrying the ball this morning, so Betty said, "But ... Mr. Oyster, if the future has developed time travel why don't we ever meet such travelers?" "The usual explanation, Betty, is that they can't afford to allow the space-time continuum track to be altered. Mr. Oyster returned his glasses to their perch, bug-eyed Simon, but then nodded. Simon said, "You want to hire me to find a time traveler and in some manner or other—any manner will do—exhort from him the secret of eternal life and youth, which you figure the future will have discovered.
 He thinks the time traveler will have the secret to never-ending youth.
 He thinks the time traveler will have the secret to never-ending youth.  He wants to know the secret of time travel and they are the best investigators around.  He wants to make sure his family's wealth continues in the future.  He wants to find out a secret for political reasons.