"I've seen the Professor's name very often in the papers," I remarked, "in connection, I think, with the British Association. I read, not long ago, an account of one of his interesting lectures at the London Institution." "Then you realise his high standing," said Kirk, interpolating an aside to Joseph. "Well, Mrs. Greer is dead, and the household at Regent's Park consists of the Professor, Ethelwynn, her maid Morgan, two housemaids, a female cook, and the butler Antonio Merli, an elderly Italian, who has been in the Professor's service for nearly twenty years. On the evening before last--that was Sunday--at twenty minutes to five o'clock, the Professor and his daughter were together in the large upstairs drawing-room, which overlooks the park, where Antonio served tea. Five minutes later Antonio re-entered and handed his master a telegram. The Professor, having read it, placed it upon the fire, and remarked that he would be compelled to go to Edinburgh that night by the 11:30 from King's Cross, but would return in three days' time, for the girl had accepted an invitation for the grand ball at Sutherland House to-morrow." "The Professor sent no reply to the message?" I asked, much interested. "No; but half an hour later his actions struck his daughter as somewhat peculiar, for, having suddenly glanced up at the clock, he rose, crossed to one of the three long windows--the end one--and drew up the blind. Then, after a pause, he lowered it again. Then twice he pulled it up and down quickly, and returned again to where he was sitting. At least, that is his daughter's story." "He signalled to somebody--using the Morse code, I should say." "Exactly my theory, Mr. Holford. I note that you follow me," exclaimed the friendless man. "You possess a keen sense of deduction, I see!" "Apparently you don't believe this statement of Miss Ethelwynn's?" I said. He sniffed quickly, but did not at first reply. "The fact that he drew the blinds up and down at a preconcerted hour shows that he communicated with somebody who was awaiting the signal outside in Regent's Park," he remarked at last. "Well, what then?" "At eight he dined, as usual, with his daughter, and after dinner the faithful Antonio packed his kit-bag and suit-case, putting in only sufficient clothes for a stay of three days. At her father's order Ethelwynn telephoned to the station-master's office at King's Cross and secured a sleeping berth in the 11:30 express for Edinburgh. At a quarter to eleven o'clock he kissed his daughter good night, and went away in a cab to the station, promising faithfully to be back to take her to the ball." "And he disappeared--I suppose?" "No, he didn't," my companion exclaimed, as, turning to the bird, he said, "Mr. Holford jumps to conclusions just a little too quickly, doesn't he, Joseph?" And he slowly relit his pipe, which had again gone out.