Colin's only reply was a nod, and the three of them sat in silence until the door opened and Mrs. Ramsay appeared on the threshold, with the massive form of Mr. Medwin looming up behind her.
The solicitor, who was wearing a frock-coat and carrying a top hat in his hand, took a couple of paces forward. Then with an air of surprise he came to a sudden halt.
The Inspector rose instantly.
"Let me introduce myself, Mr. Medwin. I am Inspector Marsden, of Scotland Yard."
Mr. Medwin bowed, his close-set eyes travelling swiftly over the other occupants of the room.
"Good morning," he said, in that peculiarly suave voice of his. "May I inquire what all this signifies?"
"Professor Carter has been murdered."
Marsden's answer came with startling bluntness, and there could be no question as to the effect that it produced. An expression of incredulous amazement flashed across the big man's face, and for a moment he stood gripping his hat and staring blankly at the speaker.
"Murdered?" he exclaimed at last. "Impossible! There must be some mistake."
"It's not the sort of thing that lends itself to mistakes," returned the detective.