“There’s one clue and there’s one clue alone,” he said, and drew from his pocket a soft hat. “Do you recognise this, Anderson?”
Timothy nodded.
“Yes,” he said, “that was worn last night by the man I spoke to you about.”
“Cartwright?” said the detective.
“I could swear to it,” said Timothy. “Where did you find it?”
“Outside,” said the detective; “and that is all we have to go on. There is no sign of any body. My first theory stands.”
“You believe that the murderer carried Sir John and Lady Maxell into the car and drove away with them?” said Timothy; “but that pre-supposes that the chauffeur was in the plot.”
“He may have been and he may have been terrorised,” said the detective. “Even a taxi-driver will be obliging if you stick a gun in his stomach.”
“But wouldn’t Miss Maxell have heard——” began Timothy.
“Miss Maxell heard,” said the detective, “but was afraid to look out. She also heard two shots. My theory is that Sir John and Lady Maxell were killed, that the murderer first locked both the bedrooms, went through Sir John’s papers, presumably to discover something incriminating himself, and to destroy such documents.”