"Colin, my lad," he said, "here's my blessing and my congratulations! Nancy's a million times too good for you, but——"
As he spoke the telephone bell rang sharply, and Colin, who was sitting nearest the door, jumped to his feet.
"I'll go," he said. "You finish your speech, Mark. It would be a pity to break off just when you're getting really truthful."
He hurried out into the hall and took down the receiver.
"Is that 276 Shadwell?"
"It is," he answered.
"Inspector Marsden of Scotland Yard speaking. Is Doctor Gray in?"
"He's not only in, but he's talking to you," returned Colin.
"I thought it was your voice," came the reply. "Look here, doctor, I've got back a bit earlier than I expected, and I want to see you as soon as possible. Can you come up to the Yard straight away?"
"I can be there in half an hour," said Colin.