"I stood gazing down at the dead man, for I had turned out the lamp which I had lighted only a second before, and waited in the dark, my brain whirling. Paul had left the door partly open and I not only heard but saw Betty and Nash and Miss Ward enter Paul's bedroom. Every instant I expected to hear an outcry when they discovered Paul was not in the bed. The suspense was something frightful"--his voice shook, and he steadied it with an effort. "Peering out from behind the door I saw Nash and Betty leave, and Miss Ward return to Paul's bedroom. There followed a slight cry, a heavy fall, and then silence. I waited for a second or two, then crept across the hall and into the bedroom. Miss Ward was lying in a faint on the floor, and Paul's bed was empty." "So, fearing she would revive too soon, you chloroformed her and carried Paul's dead body into the room and put it into his bed," completed Trenholm, as Roberts broke down, unable to go on. "How did you lose the letter?" "I don't know--it is the one confused incident of the night," replied Roberts, after some hesitation. "The letter must have flown out of my hand as I struck at Paul." Roberts sighed heavily. "It happened that Paul fell on some soiled sheets which Martha had thrown on the floor, intending to take away the next morning. I used the sheets and a woman's scarf to staunch the flow of blood and gave them, with my driving gloves, which I had not removed, to Corbin to destroy. There was nothing to indicate that Paul had been in this bedroom, nothing to link me with the crime." Roberts sighed again. "Then an overwhelming terror and an unspeakable horror of what I had done drove me out of the house and I did not come again into this bedroom to make a search for the letter. The next morning Alan and Trenholm and the coroner gave me no time alone, and then came Mrs. Nash and she was put in here--and with her awake in the daytime and Miss Ward on duty at night"--Roberts' gesture was eloquent as he looked at Trenholm. "Well, you beat me. But I'd like to know where you found the letter and how you discovered the code." "Miss Ward did both," replied Trenholm as they looked at him. "She found the letter in that chair," pointing to it, "tucked under the upholstery and the seat cushion where it evidently had fallen; and she suspected that a code was concealed in the peculiar use of five one-cent Canadian stamps, in place of the regular three-cent postage, on thirteen letters. We deciphered the code--and this message:--" "Well?" questioned Roberts eagerly, as he paused. "What?" "'Watch thirteenth letter suicides grave,'" repeated Trenholm, and his listeners gazed at him blankly. Turning abruptly to Betty, he addressed her. "Did you take some photographs of this house a little while ago, and one of this room?"