question:  Why are Reston-Farrell and Brett-James not willing to assassinate Temple-Tracy themselves?
context: A gun is an interesting weapon; it can be hired, of course, and naturally doesn't care who hires it. The evening was dark, it was unlikely that the other even saw the circle of steel that was the mouth of the shotgun barrel, now resting on the car's window ledge. And at that moment, the universe caved inward upon Joseph Marie Prantera. Lawrence Reston-Farrell said, "You are not being constrained. It opened on his approach, the door sliding back into the wall in much the same manner as the room's door had opened for Reston-Farrell. Reston-Farrell said, "I am afraid, Mr. Salviati-Prantera, that these are the only garments available. Reston-Farrell said compassionately, "Try this, it's excellent cognac." Two were seated there now, papers, books and soiled coffee cups before them. Reston-Farrell, the one Joe had already met, was tall and drawn of face and with a chainsmoker's nervousness. Reston-Farrell said, "May I present my colleague, Citizen Warren Brett-James? Reston-Farrell said, "Of course," and then something else Joe didn't get. Whatever the something else was, a slot opened in the middle of the table and a glass, so clear of texture as to be all but invisible, was elevated. Warren Brett-James said soothingly, "Prepare yourself for somewhat of a shock, Mr. Prantera. Reston-Farrell said, "I am afraid we are confusing you. Reston-Farrell said, "Suffice to say, you are now one hundred and seventy-three years after the last memory you have." Reston-Farrell said, "Mr. Prantera, we have brought you from your era to perform a task for us." For the second time, Reston-Farrell said, "Where would you go, Mr. Prantera?" The two men of the future said nothing more for long minutes while Joe Prantera's mind whirled its confusion.
output:  They do not possess hatred in their genetic sequence and are incapable of committing vile acts
options:  They would feel such guilt after taking a fellow human's life as to cause them long-lasting anguish  They are fearful of Temple-Tracy's followers using him as a martyr to strengthen their cause  They are afraid of what might happen if they are forced to receive psychiatric treatment  They do not possess hatred in their genetic sequence and are incapable of committing vile acts