46214    The one is whether any crime has been committed at all, the second is, what is the crime and how was it committed?

46215    Of course, if Dr Mortimer's surmise should be correct, and we are dealing with forces outside the ordinary laws of Nature, there is an end of our investigation.

46216    But we are bound to exhaust all other hypotheses before falling back upon this one.

46217    I think we'll shut that window again, if you don't mind.

46218    It is a singular thing, but I find that a concentrated atmosphere helps a concentration of thought.

46219    I have not pushed it to the length of getting into a box to think, but that is the logical outcome of my convictions.

46220    Have you turned the case over in your mind?'

46221    'Yes, I have thought a good deal of it in the course of the day.'

46222    'What do you make of it?'

46223    'It is very bewildering.'

46224    'It has certainly a character of its own.

46225    There are points of distinction about it.

46226    That change in the footprints, for example.

46227    What do you make of that?'

46228    'Mortimer said that the man had walked on tiptoe down that portion of the alley.'