"What sort of stuff do you mean? Not any kind of poison?"
"Good Lord, no! That would be asking for trouble. This must be a natural death; there's no good attempting anything else. Here's the thing I propose to use."
"What is it? It looks harmless."
"Simply tetanus."
She thought that her heart entirely stopped beating. Tetanus! Gripped by a sickening fear she forced herself to lie quite still, while waves of horror passed over. She heard as in a dream the stifled ejaculation of the young man.
"Tetanus … why, God in heaven, that's lock-jaw!"
"Quite. The anti-toxin for it has been discovered, as a matter of fact. I have discovered it. However, that is not known to the public yet; it was very recent."
There was the sound of a long-drawn, shuddering gasp.
"But how do you mean to … won't it be dangerous?" Holliday faltered.
"As it happens it is quite simple—a piece of luck. In fact that is why I thought of tetanus. It seems Clifford has been going about for nearly a week with an open cut on his thumb. Half the time there's no bandage on it, although I've warned him more than once of the risk of infection. This morning his aunt persuaded him to let me disinfect it properly and bandage it. So that is what I am going to do when I get back this evening."