“There is no need to alarm your wife or to tell her the details of our conversation,” pursued the other quietly. “Let her know that you will soon be in possession again of your sense of humour and your health, and explain that I am lending you another house for six months. Meanwhile I may have the right to use this house for a night or two for my experiment. Is that understood between us?”

“I can only thank you from the bottom of my heart,” stammered Pender, unable to find words to express his gratitude.

Then he hesitated for a moment, searching the doctor’s face anxiously.

“And your experiment with the house?” he said at length.