The corridor? I stopped. My thoughts suddenly took a new direction, uninfluenced by any effort of my will. What other association besides the association with Dexter did I connect with the corridor? Was it something I had seen during my visit to Gleninch? No. Was it something I had read? I snatched up the Report of the Trial to see. It opened at a page which contained the nurse’s evidence. I read the evidence through again, without recovering the lost remembrance until I came to these lines close at the end: “Before bed-time I went upstairs to prepare the remains of the deceased lady for the coffin. The room in which she lay was locked; the door leading into Mr. Macallan’s room being secured, as well as the door leading into the corridor. The keys had been taken away by Mr. Gale. Two of the men-servants were posted outside the bedroom to keep watch. They were to be relieved at four in the morning--that was all they could tell me.” There was my lost association with the corridor! There was what I ought to have remembered when Miserrimus Dexter was telling me of his visit to the dead! How had he got into the bedroom--the doors being locked, and the keys being taken away by Mr. Gale? There was but one of the locked doors of which Mr. Gale had not got the key--the door of communication between the study and the bedroom. The key was missing from this. Had it been stolen? And was Dexter the thief? He might have passed by the men on the watch while they were asleep, or he might have crossed the corridor in an unguarded interval while the men were being relieved. But how could he have got into the bedchamber except by way of the locked study door? He _must_ have had the key! And he _must_ have secreted it weeks before Mrs. Eustace Macallan’s death! When the nurse first arrived at Gleninch, on the seventh of the month, her evidence declared the key of the door of communication to be then missing. To what conclusion did these considerations and discoveries point? Had Miserrimus Dexter, in a moment of ungovernable agitation, unconsciously placed the clew in my hands? Was the pivot on which turned the whole mystery of the poisoning at Gleninch the missing key? I went back for the third time to my desk. The one person who might be trusted to find the answer to those questions was Mr. Playmore. I wrote him a full and careful account of all that had happened; I begged him to forgive and forget my ungracious reception of the advice which he had so kindly offered to me; and I promised beforehand to do nothing without first consulting his opinion in the new emergency which now confronted me. The day was fine for the time of year; and by way of getting a little wholesome exercise after the surprises and occupations of the morning, I took my letter to Mr. Playmore to the post. Returning to the villa, I was informed that another visitor was waiting to see me: a civilized visitor this time, who had given her name. My mother-in-law--Mrs. Macallan.