"But your eyes——" stammered Alice "Can you see, father?"
"See, my dear? What does she mean, Dr. Harden?"
"There is some discolouration of the conjunctivæ," I said hastily. "It is nothing to worry about."
At that moment Alice caught sight of his finger nails.
"Look!" she cried, "they're blue."
The old man raised his hands and looked at them in astonishment.
"How extraordinary," he murmured. "What do you make of that, doctor?"
"It is nothing," I assured him. "It is only pigmentation caused—er—caused by some harmless germ."
"I know what it is," cried Alice suddenly. "It's the Blue Disease. Father, you remember the Perrys were telling us about it yesterday at lunch. They said it was all over Birmingham, and that they had come south partly to escape it. They must have brought the infection with them."
"Yes," I said, "that is certainly the explanation. And now, Mr. Annot, let me assure you that this disease is harmless. It has no ill effects."