“Which is fortunate for you, Jervis. If she had not been in such a fluster, she would have waited until you had poured out your tea, which was what she probably meant to do, or have dropped the sugar into the milk-jug. In either case you would have got a poisonous dose before you noticed anything amiss.”

“They are a pretty pair, Thorndyke,” I exclaimed. “A human life seems to be no more to them than the life of a fly or a beetle.”

“No; that is so. They are typical poisoners of the worst kind; of the intelligent, cautious, resourceful kind. They are a standing menace to society. As long as they are at large, human lives are in danger, and it is our business to see that they do not remain at large a moment longer than is unavoidable. And that brings us to another point. You had better keep indoors for the next few days.”

“Oh, nonsense,” I protested. “I can take care of myself.”