for an argument. "But if it be that the patient has used some strange
drug, it may be one that does not take effect at once. As we are as yet
ignorant of its potentialities--if, indeed, the whole surmise is correct
at all--we must be prepared at all points."

Here Miss Trelawny joined in the conversation:

"That would be quite right, so far as the action of the drug was
concerned; but according to the second part of your surmise the wound
may have been self-inflicted, and this after the drug had taken
effect."

"True!" said the Detective and the Doctor simultaneously. She went on:

"As however, Doctor, your guess does not exhaust the possibilities, we
must bear in mind that some other variant of the same root-idea may be
correct. I take it, therefore, that our first search, to be made on
this assumption, must be for the weapon with which the injury was done
to my Father's wrist."

"Perhaps he put the weapon in the safe before he became quite
unconscious," said I, giving voice foolishly to a half-formed thought.

"That could not be," said the Doctor quickly. "At least I think it
could hardly be," he added cautiously, with a brief bow to me. "You
see, the left hand is covered with blood; but there is no blood mark
whatever on the safe."

"Quite right!" I said, and there was a long pause.