die."

"I quite agree with you, sir. But we've no evidence that he is going to
die. His friends sent for you, and you treated him skilfully and left
him in a fair way to recovery. That's all that we really know about it.
Yes, I know," the officer continued as I made signs of disagreement,
"you think that a crime is possibly going to be committed and that we
ought to prevent it. But you overrate our powers. We can only act on
evidence that a crime has actually been committed or is actually being
attempted. Now we have no such evidence. Look at your statement, and
tell me what you can swear to."

"I think I could swear that Mr. Graves had taken a poisonous dose of
morphine."

"And who gave him that poisonous dose?"

"I very strongly suspect--"

"That's no good, sir," interrupted the officer. "Suspicion isn't
evidence. We should want you to swear an information and give us enough
facts to make out a primâ facie case against some definite person. And
you couldn't do it. Your information amounts to this: that a certain
person has taken a poisonous dose of morphine and apparently recovered.
That's all. You can't swear that the names given to you are real names,
and you can't give us any address or even any locality."

"I took some compass bearings in the carriage," I said. "You could
locate the house, I think, without much difficulty."