My instinctive suspicion was of Horatio Paget. And yet, was it not more probable that Theodore Judson, senr. and Theodore Judson, junr. were involved in this business, and were watching and counterchecking my actions with a view to frustrating the plans of my principal? This was one question which I asked myself as I deliberated upon this mysterious business. Had the Theodore Judsons some knowledge of a secret marriage on the part of Matthew Haygarth? and did they suspect the existence of an heir in the descendant of the issue of that marriage? These were further questions which I asked myself, and which I found it much more easy to ask than to answer. After having considered these questions, I went to the Lancaster-road, saw Miss Judson--assured her, on my word as a gentleman, that the packet had been delivered by my hands into those of the waiter at eleven o'clock on the previous day, and asked to see the envelope. There it was--my large blue wire-wove office envelope, addressed in my own writing. But in these days of adhesive envelopes there is nothing easier than to tamper with the fastening of a letter. I registered a mental vow never again to trust any important document to the protection of a morsel of gummed paper. I counted the letters, convinced myself that there was a deficiency, and then set to work to discover which of the letters had been abstracted. Here I failed utterly. For my own convenience in copying my extracts, I had numbered the letters from which I intended to transcribe passages before beginning my work. My pencilled figures in consecutive order were visible in the corner of the superscription of every document I had used. Those numbered covers I now found intact, and I could thus assure myself that the missing document was one from which I had taken no extract. This inspired me with a new alarm. Could it be possible that I had overlooked some scrap of information more important than all that I had transcribed? I racked my brains in the endeavour to recall the contents of that one missing letter; but although I sat in that social tomb, Miss Judson's best parlour, until I felt my blood becoming of an arctic quality, I could remember nothing that seemed worth remembering in the letters I had laid aside as valueless. I asked Miss Judson if she had any suspicion of the person who had tampered with the packet. She looked at me with an icy smile, and answered in ironical accents, which were even more chilling than the atmosphere of her parlour,--