 How has Simon manipulated Mr. Oyster?
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. When Simon continued to say nothing she ventured, "Time travel is impossible." "Then you'll realize that there are a dozen explanations of the paradoxes of time travel. 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 went on. 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 has traveled back in time thrice to attempt to bring back a time traveler
 He has traveled back in time thrice to attempt to bring back a time traveler  He has taken over $50,000 of Mr. Oyster's money based on unfulfilled investigations  He has discovered that Mr. Oyster is actually Arth from several decades ago  He has used the opportunity to travel to Oktoberfest on vacation, and never intended to grant Mr. Oyster's request