So at length, full of grave apprehensions, I left Aix, sickened by its music and summer gaiety, and travelled home, halting one night at the Grand in Paris, and duly arrived at the Cecil in London. There I found a batch of letters sent on to me from Upton End, and among them was a formal letter from a firm of solicitors called Napier and Norman, 129, Bedford Row, W.C., stating that they were acting for the late Mr Guy Nicholson of Titmarsh Court, and asking me to call upon them without delay. Exercising caution lest I should be watched, I had immediately on arrival telephoned from my hotel bedroom to Lydford, but the response came back in a woman's voice that "the master" and Miss Asta were still abroad. Therefore about noon on the morning following my return I went round to Bedford Row in a taxi, and was quickly shown into the sombre private room of an elderly, quiet-spoken man--Mr George Napier, head of the firm. "I'm extremely glad you have called, Mr Kemball," he said, as he leaned back in his chair. "I believe you were present at Titmarsh very soon after the unfortunate death of our client, Mr Guy Nicholson. Indeed, I remember now that we met at the inquest. Well, Mr Nicholson, with his father and grandfather before him, entrusted his affairs in our hands, and, naturally, after his decease we searched his effects for any papers that were relative to his estate, or any private papers which should not fall into anybody's hands. Among them we found this letter, sealed just as you see it, and addressed to you. He evidently put it aside, intending to post it in the morning, but expired in the night." And taking a letter from a drawer in his writing-table, he handed it across to me. I glanced at the superscription, and saw that it was addressed ready for the post and that a stamp was already upon it. "Poor Nicholson's death was a most mysterious one," I exclaimed, looking the solicitor full in the face; "I don't believe that he died from natural causes." "Well, I fear we cannot get away from the medical evidence," replied the matter-of-fact, grey-faced man, peering through his spectacles. "Of course the locked door was a most curious circumstance--yet it may be accounted for by one of the servants, in passing before retiring, turning the key. Or, as you suggested at the inquest, the servant who entered the library in the morning may have thought the door was locked. It might have caught somehow, as locks sometimes do." I shook my head dubiously, and with eager fingers tore open the message from the dead. From its date, it had evidently been written only a few hours prior to his untimely end, and it read-- "Strictly Private.