"Just as you please, sir," said Colin, pushing back his chair. "I suppose it would be no use my suggesting that you should try a little of the same prescription yourself?"
The Professor shook his head. "I am more favourably situated than you, my young friend," he replied. "In the course of nature I shall soon have all the rest that I need." He chuckled at his own sombre jest, and, coming forward, laid his hand on Colin's shoulder. "You have been of very real assistance, to me, Gray," he added, "but there is no sense in flogging a willing horse. I can quite well spare you to-day, so off you go, whether you like it or not."
Colin, who had been long enough at the Red Lodge to know the futility of arguing, at once rose to his feet.
"I will see if I can rout out Mark Ashton," he said, "that doctor pal of mine I was telling you about the other day. I should think that with any luck we ought to be able to carry on until midnight."
He accepted a cigar which the Professor offered him, and, making his way to the telephone in the hall, rang up the Shadwell surgery.
"Hullo!" came a voice, "Who's that? Colin? Why, good Lord, man, we thought you were dead!"
"Why should I be dead?" retorted Colin. "I'm not one of your patients."
He heard a laugh at the other end of the wire.
"As a matter of fact," he continued, "I'm just starting off to pay you a visit."
"Splendid!" was the answer. "Mary's still away up North, but you'll find me here, and Miss Seymour, too. What more could you want?"