Inch by inch, down on his knees, carefully avoiding any touch with the
stains on the floor, he followed the blood-marks over to the spot, close
under the great safe, where the body had lain. All around and about
this spot he went for a radius of some yards; but seemingly did not meet
with anything to arrest special attention. Then he examined the front
of the safe; round the lock, and along the bottom and top of the double
doors, more especially at the places of their touching in front.

Next he went to the windows, which were fastened down with the hasps.

"Were the shutters closed?" he asked Miss Trelawny in a casual way as
though he expected the negative answer, which came.

All this time Doctor Winchester was attending to his patient; now
dressing the wounds in the wrist or making minute examination all over
the head and throat, and over the heart. More than once he put his nose
to the mouth of the senseless man and sniffed. Each time he did so he
finished up by unconsciously looking round the room, as though in search
of something.

Then we heard the deep strong voice of the Detective:

"So far as I can see, the object was to bring that key to the lock of
the safe. There seems to be some secret in the mechanism that I am
unable to guess at, though I served a year in Chubb's before I joined
the police. It is a combination lock of seven letters; but there seems
to be a way of locking even the combination. It is one of Chatwood's; I
shall call at their place and find out something about it." Then
turning to the Doctor, as though his own work were for the present done,
he said: