“I think,” he replied, “that if you examine them with due consideration, you will find their use pretty obvious. Have a good look at them and the spectacles too. Think over all that you know of that mysterious group of people who lived in that house, and see if you cannot form some coherent theory of their actions. Think, also, if we have not some information in our possession by which we might be able to identify some of them, and infer the identity of the others. You will have a quiet day, as I shall not be home until the evening; set yourself this task. I assure you that you have the material for identifying⁠—or rather for testing the identity of⁠—at least one of those persons. Go over your material systematically, and let me know in the evening what further investigations you would propose.”

“Very well,” said I. “It shall be done according to your word. I will addle my brain afresh with the affair of Mr. Weiss and his patient, and let the Blackmore case rip.”