Looking back, Ione Muir was to wonder what would have happened if she had chosen any other day to go up to town. With all the days of the week to choose from, she had picked a Tuesday, and that particular Tuesday. Suppose she had chosen some other day. Suppose she had gone a week earlier or a week later. Suppose she had not gone at all. Just how much difference would it have made? Would she have met Jim Severn in some other way? Would it all have been the same in the end? Or would it have been different—perhaps dreadfully different? Did certain people, certain events, certain crimes, produce as it were a vortex into which you must inevitably have been drawn? Or did it all just turn on the choice of a day or a train? She was never to be quite sure.