 Why is Doc struggling with a man at the beginning?
I admit it: I didn't know if I was coming or going—but I know that if I stuck to the old man, I was a comer ... even if he was a goner! The golden Moon and the silver ship, symbols of greed. "Sure," the man agreed severely, prying a little worriedly at Doc's arthritic fingers that were clamped on his collar. I came alongside and carefully started to lever the old man loose, one finger at a time. If a half dozen winos in Seattle hadn't helped me get them loose, Doc and I would have been wanted for the murder of a North American Mountie. Doc's thin frame, layered with lumpy fat, was beginning to muscle-dance against my side. "'Memory Jump,' you mean. All my great-grandfathers have it. I told the human no, thanks, and walked Doc toward the flophouse three doors down. They weren't men like Doc and me. It had happened a few times right after I first found him, but now it was worse. I tried not to think about it and helped Doc through the fly-specked flophouse doors. The clerk's hand fell on the coin and slid it off into the unknown before I could move, what with holding up Doc. "Had a quarter all along and yet you Martian me down to twenty cents." You don't have any quarter, not if I say so. It stopped hurting, but I knew it would begin if I moved. I found I couldn't focus both my mind and my eyes through the electric flashes of agony, so I concentrated on Doc's voice and trusted my hands would follow their habit pattern and construct the symbols for his words. Beyond Six, Seven, Eight ... Somehow, inside me, I knew that these words were what I had been waiting for. They told everything I needed to know to become the most powerful man in the Solar Federation. When I got to thinking it was just a dream and that I was dragging this old man around North America for nothing, I remembered who he was. I remembered that he was somebody very important whose name and work I had once known, even if now I knew him only as Doc. Pain was a pendulum within me, swinging from low throbbing bass to high screaming tenor. I listened to him for a moment, then tested and tasted the craving that crawled through my veins. He shut up at last and I laid him down again and put his arm back across his face.
 Doc was in the throes of withdrawal and was easily upset, latching on to the closest person he saw
 The man had insulted the narrator, and he couldn't stand for that, so he attacked him  Doc was trying to get information from the man that he was refusing to share  Doc was in the throes of withdrawal and was easily upset, latching on to the closest person he saw  The other man was argumentative and didn't think Doc knew the truth about the story he was telling