“For the moment, nothing. Leave it now in my hands, and be assured that I will do all that is humanly possible to protect your son.”

They were not exactly reassuring words, and I observed Lady Willard wince as he uttered them. Yet, at the same time, the fact that he had not pooh-poohed her fears seemed in itself to be a relief to her.

For my part I had never before suspected that Poirot had so deep a vein of superstition in his nature. I tackled him on the subject as we went homewards. His manner was grave and earnest.

“But yes, Hastings. I believe in these things. You must not underrate the force of superstition.”

“What are we going to do about it?”