I can relate Vanish. I went up to a prime knob and got a gobbler to respond to my calls about 500 or so feet below me with an hour of daylight left. I made a mad dash downhill while trying to keep him talking. I know I was close, probably 100 yards or less with 15 minutes of light left and he went totally silent. Maybe I came in too fast and he knew something was up or he was just being a turkey. Nice to get into a bird though.