human
On the other hand, the few drops of toxin in the glass possessed every advantage from the unknown's standpoint. It was invisible, and as sure in its action as the venom. Also it was as rare and as difficult to trace. For, remember this. Botulism is food poisoning. If I had not found the stem of that glass it would be absolutely impossible to show that Werner died from anything on earth but bad food. That is why I do not even take time to analyze the stomach contents. That is why I say we are confronted by an archscoundrel of highest intelligence and downright cleverness. More --Kennedy paused for emphasis--
gpt
I realize now the presence of a grim, invisible menace. It has just now been driven home to me. The botulin, with its deadly paralyzing power, sealed Werner's tongue even while he tried to tell me what he knew.
human
Does this mean, he asked,
gpt
There are two possibilities, Kennedy answered.
human
The real person behind the two murders may have employed some one else to carry out the actual killing, a hypothesis I do not take seriously, or --again he paused--
gpt
What is the invisible menace of which you spoke, Craig?
human
The possibility of another murder before we can apprehend the guilty person or gain the evidence we need.
gpt
Good heavens! I imagine I blanched.
human
You mean--
gpt
Werner was struck down, apparently, for no reason but that he had guessed the identity of the villain. There is a second man in the company who has certain suspicions and is acting upon them. If he is on the right trail, by any chance--
human
Shirley?
gpt
Exactly! And there is still another possibility.
human
What is that?
gpt
Here in this laboratory I have blood spots made on the portieres at the house of Phelps by the man who removed the needle, probably the unknown himself, possibly his--or her--agent. In any case it is a clue and--THE ONLY DIRECT AND INFALLIBLE CLUE IN EXISTENCE TO THE CRIMINAL! Also I have the evidence of the snake venom and of the botulin toxin here. Sooner or later the person who killed Werner because he suspected things will wake up to the fact that we possess tangible proof against him.
human
You mean, then, that you may be attacked yourself? That even I--