He put a note down on the table beside me. I took it and read as follows: +Dear Gernham+—I don’t know whether you will come to-day; but should you do so, I’ve told Cragg to give you this. I did not care to quarrel with a man in my own house; and so yesterday, when you were impertinent to me, I did not appear to resent it. As you know, I admire your character and respect your enthusiasm, and it has been a great pleasure to me to be associated with you in a work which I love with my whole heart and soul. But I allow no man to criticise my conduct as you have chosen to criticise it. I am sorry, therefore, that unless you feel inclined to apologise, I cannot admit you to my house.—Believe me, faithfully, +Vernon Kersteven+. “What do you think of that, eh?” asked Gernham, when I finished reading the note. “Pretty blunt, isn’t it?” “Vernon has decidedly got up,” I said. I looked again at the note. “Tell me just what you think,” Gernham said. “Well,” I answered, with some hesitation, “it’s an abrupt change of front after his behaviour yesterday.” “Too abrupt,” he said. “I don’t like it; I don’t like it at all. You were right, Luttrell; there is a mystery here—a mystery connected with that dog. But I haven’t got your opinion yet!” He was a persistent man, and did not readily lose sight of his object. “You want to know how I explain Vernon’s change of front.” “Exactly.” “It seems to me that he has thought things over since yesterday, and resolved to avail himself of this pretext to keep you out of his house.” “That’s it!” exclaimed Gernham. “I’ve given him his opportunity like a fool, and he’s taken it, like a clever man. But where an animal is concerned I’m not so easily dished. A good many people who’ve appeared in the London police-courts know that.” “When you got this note, what did you do?” “I tried to question Cragg.” “And the result?” “Nil. Directly I mentioned the dog, he looked as grim as death, and became monosyllabic. There’s something up, and Cragg has an inkling of it. But he’ll never tell it to me. You’ve got to go into this, Luttrell.” At this moment lunch was announced, and the rest of the conversation took place in the dining-room. Directly after lunch Gernham hurried away, leaving me pledged to act where he could not act, pledged to probe to the bottom, and without delay, the mystery of the black spaniel.