"Shall we call that Conundrum Number Six?" Mr. Thomson suggested, watching the ash on his cigar. "You understand, of course, that we are going to have a grand finale. You have a week in which to rest, and I think a study of your banking account will prove that you are justified in taking a holiday if you wish to. On next Thursday evening, at six o'clock, I desire that all three of you will be at the rooms which you are now occupying in Clarges Street. You will there receive a message from me. I shall ask your help once more before I retire into private life--and safety." The music surged in our ears, and the froth of light conversation filled the air. Of all the little groups of people seated about, we alone seemed to have our faces set towards the serious things. Perhaps our host noticed it, for he rose to his feet and drew Leonard on one side. "If I were your age, Lister," he said, turning to me, "I should ask Miss Mindel to drift about with me in one of those shadowy boats." So Rose and I strolled down towards the lake. "To think," she murmured, a little tremulously, "that very soon we shall come to the end of our adventures!" I drew her arm through mine. The sound of the music was growing fainter in the distance and the ripple of the water was in our ears. "Or to the beginning," I whispered. CONUNDRUM NUMBER SEVEN THE GREATEST ARGUMENT The clock had scarcely finished striking six when a two-seated car, throaty but sonorous, came to a standstill in front of the house in Clarges Street where Rose, Leonard and I had our temporary abode. An elegantly dressed but weary young man was shown into our sitting room. He bowed to Rose and addressed me. "You're Maurice Lister, what, and Mr. Leonard Cotton?" he began. "No use telling you my name because you wouldn't know it. I've brought you a message." I indicated a chair but our visitor shook his head. "Got to be tooting off in a moment," he continued. "I have just come from the old man. He's in a nursing home round the corner." "What, Mr. Thomson?" I exclaimed. The young man assented, although at the mention of the name he winced. "They nearly laid him out last night in Lansdowne Passage," he announced. "Fortunately, I wasn't far away. Number 100, John Street. He'd like you there in a quarter of an hour, Mr. Lister." "But who laid him out?" I asked. "Is he seriously hurt?" Leonard intervened, holding out a newspaper. "There's an account here!" he exclaimed. "'Murderous assault in Lansdowne Passage.' They say the victim, name unknown, is in a precarious condition." "Was that really Mr. Thomson?" Rose demanded, in a shocked tone. "Less said, less trouble," the young man replied, embracing us all in a common farewell salute. "So long."