Robin produced the pistol he had taken from Jeekes. Herr Schulz slipped a Browning pistol into the breast-pocket of his jacket and, producing a long-barrelled service revolver, gave it to the doctor. “There are three of them, I gather, counting the chauffeur,” commented the big man, pulling on his overcoat, “so we shall be equally matched.” Darkness had fallen upon Rotterdam and the lights from the houses made yellow streaks in the water of the canal as the car, piloted by Robin, drove the party to Mary Trevert’s hotel. They found the girl, pale and anxious, in the lounge. “Well, now,” cried the doctor breezily, “and how are you feeling? Did you take my advice and have some tea?” “What has happened?” asked the girl; “I have been so anxious about you ...” Her words were addressed to the doctor, but she looked at Robin. “Mary,” said Robin, “we are very near the truth now. But there is one thing you can tell us. It is very important. When you heard the shot in the library at Harkings, did you notice any other sound—before or after?” The girl paused to think. “There was a sort of sharp cry and a thud ...” “I know. But was there anything else? Do try and remember. It’s so important!” The girl was silent for a moment. Then she said slowly: “Yes, there was, now I come to think of it. Just as I tried the door—it was locked, you know—there was a sort of hiss, harsh and rather loud, from the room ...” “A sort of hiss, eh? Something like a sneeze?” “Yes. Only louder and ... and ... harsher!” “Now, answer me carefully! Was this before or after the shot?” “Oh, before! Just as I was rattling the doorhandle. The shot broke in upon it....” Robin turned to Herr Schulz, who stood with a grave face by his side. “The silencer, you see, sir!” he said. Then to Mary he added: “Mary, we are going off now. But we will be back within the hour and....” “Oh, Robin,” the girl broke in, “don’t leave me alone! I don’t feel safe in this place after this morning. I’d much rather come with you....” “Mary, it’s quite impossible....” Robin began. But the girl had turned to a table and taken from it her hat and fur. “I don’t care!” she exclaimed wilfully; “I’m coming anyhow. I refuse to be left behind!” She smiled at Herr Schulz as she spoke, and that gentleman’s rather grim face relaxed as he looked at her. “I’m not sure I wouldn’t say the same!” he remarked. The upshot of it was that, despite Robin’s objections, Mary Trevert accompanied the party. She sat on the back seat, rather flushed and excited, between Herr Schulz and the doctor, while Robin took the wheel again. A few minutes’ drive took them to the big hotel where Robin had booked a room. They all waited in the car whilst he went to the office. He was back in a minute, an open telegram in his hand. “I believe I’ve got in my pocket,” he cried, “the actual weapon with which Hartley Parrish was killed!” And he read from the telegram: