The session was over at last, and Wallbridge and Eppner handed me their memoranda of purchases. “You couldn't pick Omega off the bushes this afternoon, Mr. Wilton,” said Wallbridge, wiping his bald head vigorously. “There's fools at all times, and some of 'em were here and ready to drop what they had; but not many. I gathered in six hundred for you, but I had to fight for it.” I thanked the merry broker, and gave him a check for his balance. Eppner had done some better with a wider margin, but all told I had added but three thousand one hundred shares to my list. I wondered how much of this had been sold to me by my employer. Plainly, if Doddridge Knapp was needing Omega stock he would have to pay for it. There was no one to be seen as I reached Room 15. The connecting door was closed and locked, and no sound came from behind it. I turned to arrange the books, to keep from a bad habit of thinking over the inexplicable. But there was nothing exciting enough, in the statutes or reports of court decisions or text-books, to cover up the questions against which I had been beating in vain ever since I had entered this accursed city. An hour passed, and no Doddridge Knapp. It was long past office hours. The sun had disappeared in the bank of fog that was rolling up from the ocean and coming in wisps and streamers over the hills, and the light was fast failing. Just as I was considering whether my duty to my employer constrained me to wait longer, I caught sight of an envelope that had been slipped under the door. I wondered, as I hastily opened it and brought its inclosure to the failing light, how it could have got there. It was in cipher, but it yielded to the key with which Doddridge Knapp had provided me. I made it out to be this: “Come to my house to-night. Bring your contracts with you. Knapp.” I was thrown into some perplexity by this order. For a little I suspected a trap, but on second thought this seemed unlikely. The office furnished as convenient a place for homicidal diversions as he could wish, if these were in his intention, and possibly a visit to Doddridge Knapp in his own house would give me a better clue to his habits and purposes, and a better chance of bringing home to him his awful crime, than a month together on the Street. The clocks were pointing past eight when I mounted the steps that led to Doddridge Knapp's door. Doddridge Knapp's house fronted upper Pine Street much as Doddridge Knapp himself fronted lower Pine Street. There was a calmly aggressive look about it that was typical of the owner. It defied the elements with easy strength, as Doddridge Knapp defied the storms of the market. I had the fancy that even if the directory had not given me its position I might have picked it out from its neighbors by its individuality, its impression of reserve force.