“It’s known as the ‘death drop’ or the ‘knock-out drop,’” said Knebworth, “and it’s a drug very much in favour with sharks who make a business of robbing sailors. A few drops of that in a glass of wine and you’re out!” Michael took the bottle again. It was a commonplace bottle such as is used for the dispensation of poisons, and in fact the word “Poison” was blown into the glass. “There is no trace of a label,” he said. “And really there is no connection with the mysterious car,” admitted the girl. “My surmise is merely guesswork—putting one sinister thing to another.” “Where was it?” “In a ditch, which is very deep there and is flooded just now, but the bottle didn’t roll down so far as the water. That is discovery number one. Here is number two.” From her bag she took a curious-shaped piece of steel, both ends of which had the marks of a break. “Do you know what that is?” she asked. “It beats me,” said Jack, and handed the find to Michael. “_I_ know what it is, because I’ve seen it at the studio,” said the girl, “and you know too, don’t you, Mr. Brixan?” Mike nodded. “It’s the central link of a handcuff,” he said, “the link that has the swivel.” It was covered with spots of rust, which had been cleaned off—by the girl, as she told him. “Those are my two finds. I am not going to offer you my conclusions, because I have none!” “They may not have been thrown from the car at all,” said Michael, “but, as you say, there is a possibility that the owner of the car chose that peculiarly deserted spot to rid himself of two articles which he could not afford to have on the premises. It would have been safer to throw them into the sea, but this, I suppose, was the easier, and, to him, the safer method. I will keep these.” He wrapped them in paper, put them away in his pocket, and the conversation drifted back to picture-taking, and, as he had anticipated: “We’re shooting at Griff Tower to-morrow—the real tower,” said Jack Knebworth. “It is one of the landmarks—what is there amusing in Griff Tower?” he demanded. “Nothing particularly amusing, except that you have fulfilled a prediction of mine,” said Michael. “I knew I should hear of that darned old tower!” CHAPTER XXVIII THE TOWER MICHAEL was a little perturbed in mind. He took a more serious view of the closed car than did the girl, and the invitation to the “pretty lady” to step inside was particularly disturbing. Since the events of the past few days it had been necessary to withdraw the detective who was watching the girl’s house, and he decided to re-establish the guard, employing a local officer for the purpose.