Colin, who had heard nothing of Joe since they had parted outside the station, received the news with no little interest. "Did he mention any particular time?" he asked. "No, sir. 'E just said 'e'd look round again later." "Well, let me know at once if he does," he replied. "I'll see him immediately, no matter how many people are waiting." Martha Jane nodded. "There's a letter and a telegram come for you too, sir. They're over there on the hall table." She paused. "Per'aps as Miss Nancy's out you'd like your tea in the surgery?" "Yes, that will be best," said Colin. "You can bring it along in as soon as it's ready." He divested himself of his coat, and, crossing to the table, picked up the telegram. As he expected, it bore the Lincoln postmark, and with eager fingers he slit open the flap and pulled out the contents. "Operation a complete success. Shall be home to-morrow about one.--MARK." He turned to Martha Jane. "This is from Doctor Ashton," he said. "Everything has gone off splendidly, and he hopes to be back to-morrow." "'E would," was the answer. "Wild 'orses wouldn't keep 'im from work, not so long as 'e's got a breath in his body." Colin laughed, and, taking up the letter, walked forward into the surgery. A bright fire was burning away cheerfully in the grate, and, having flicked on the electric light, he seated himself at his desk and proceeded to open the envelope. A single glance at the letter inside showed him that it was from Inspector Marsden. "SCOTLAND YARD, "Thursday, December 12th. "DEAR DOCTOR GRAY,--You will be interested to hear that we have at last managed to pick up the tracks of William Kennedy, Professor Carter's servant. It seems that he has been very ill, and for the last two months has been living in an out-of-the-way village in Hertfordshire under the care of an old female cousin. The latter, who is apparently unable to read, had heard nothing about the murder, and it was only last night that Kennedy was informed of the facts. I am making arrangements to motor down and interview him to-morrow, don't suppose I shall be back at the Yard until the evening, but if you would care to look in any time after six I shall be pleased to see you and to let you know the result of my journey. "I am, "Yours sincerely, "JAMES MARSDEN." With considerable satisfaction Colin folded the letter and put it away in his pocket. It was a relief to know that things were moving at last, for, even if Kennedy were unable to throw any direct light on the murder, the information he could supply with regard to the Professor's private life might well be the starting-point for further discoveries.