"Is that _the_ one?" Trent murmured as he bent over the inspector's hand. "That's him," replied Mr. Murch. "Lodged in the bone at the back of the skull. Dr. Stock got it out within the last hour, and handed it to the local officer, who has just sent it on to me. These bright scratches you see, were made by the doctor's instruments. These other marks were made by the rifling of the barrel--a barrel like this one." He tapped the revolver. "Same make, same caliber." With the pistol in its case between them, Trent and the inspector looked into each other's eyes for some moments. Trent was the first to speak. "This mystery is all wrong," he observed. "It is insanity. The symptoms of mania are very marked. Let us see how we stand. We were not in any doubt, I believe, about Manderson having despatched Marlowe in the car to Southampton, or about Marlowe having gone, returning late last night, many hours after the murder was committed." "There _is_ no doubt whatever about all that," said Mr. Murch, with a slight emphasis on the verb. "And now," pursued Trent, "we are invited by this polished and insinuating firearm to believe the following line of propositions: that Marlowe never went to Southampton; that he returned to the house in the night; that he somehow, without waking Mrs. Manderson or anybody else, got Manderson to get up, dress himself, and go out into the grounds; that he then and there shot the said Manderson with his incriminating pistol; that he carefully cleaned the said pistol, returned to the house and, again without disturbing any one, replaced it in its case in a favorable position to be found by the officers of the law; that he then withdrew and spent the rest of the day in hiding--_with_ a large motor-car; and that he turned up, feigning ignorance of the whole affair, at--what time was it?" "A little after nine P. M." The inspector still stared moodily at Trent. "As you say, Mr. Trent, that is the first theory suggested by this find, and it seems wild enough--at least it would do, if it didn't fall to pieces at the very start. When the murder was done Marlowe must have been fifty to a hundred miles away. He _did_ go to Southampton." "How do you know?" "I questioned him last night, and took down his story. He arrived in Southampton about six-thirty on the Monday morning." "Come off!" exclaimed Trent bitterly. "What do I care about his story? What do you care about his story? I want to know how you _know_ he went to Southampton."