Miss Trevor was in the habit of driving over alone to Calverton two or three times a week. Still she was never absent more than a couple of hours, and it was none of my business how she employed her leisure. Betty commented upon these journeys once or twice, but neither of us cared to press the direct inquiry; there were plenty of horses available, and the girl's time was her own; what did it matter. On this particular morning I chanced to be in the house at the moment of her return from town. She passed me in the hall, nodded briefly, and went up to her room. As I walked through the front door I noticed a letter lying on the threshold. I picked it up and saw that it was addressed to Miss Eunice Trevor, Lockbox 31, Calverton, Maryland. The handwriting was that of John Thaneford, a square, bold script with which I was perfectly familiar. The post-mark was that of a small town in Florida. So Eunice and Thaneford were engaged in correspondence, and a secret one at that. It didn't look well, and I felt the blood reddening my temples. After all she was my house guest and eating my bread and salt. Spy is an ugly word, but Thaneford was an enemy, a quiescent one for the time being, yet none the less to be guarded against. "Hildebrand Hundred" was a goodly heritage, and it would have been his had it not been for my fortuitous meeting with Francis Graeme. There were no immediate prospects that Betty would present me with an heir to the property, and I realized guiltily that I had put off the duty of making a will. Suppose that I died intestate and without issue. Betty would have her dower rights, but Thaneford could put in a plausible claim for recognition as next of kin. I made instant resolve that I would see Mr. Eldon on the morrow and erect every possible legal safeguard to conserve Betty's interests. I could rest assured that if Thaneford were able to get enough ready money he would fight for his alleged rights. In the meantime, I could do nothing but let the letter lie where it had fallen. I whistled to Gyp and strode off to the stables. At the corner of the hedge I ventured to look back, and caught just a glimpse of feminine drapery disappearing into the cavernous gloom of the great hall door. So my lady had discovered her loss, and had been prompt in retrieving her property. Very well, but I should certainly call on Mr. Eldon in the morning.