Ashton-Kirk looked at his assistant.
“Are you quite sure that our man is there,” asked he.
Burgess chewed his straw calmly.
“I’m positive of it,” said he.
The fat man now entered at the gate and going to the front door, tried it. But it was evidently fast, and he turned away. Hesitating for a moment, he laboriously approached the work shop, the roof of which could be seen through the trees. Apparently the result was the same here, for in a very few minutes he was seen to waddle back to his buggy and climb in with much effort. Then the small horse ambled forward while the fat man leaned back in great distress.
“You recognize him, do you not?” smiled Ashton-Kirk.
“I do, now,” returned Pendleton. “It’s our friend Dr. Mercer.”
When the buggy arrived at the spot where the motorcar stood, the doctor regarded its occupants with some surprise.
“Good morning,” greeted Ashton-Kirk.
Painfully, gaspingly the other answered this in kind. The round white face wore an expression of martyrdom.
“I am pleased to see you once more,” said he.
“You like driving in the morning, then?” said the investigator.
The principal’s flesh quivered with repulsion.
“It is an exercise ordered by my physician,” he answered. “I protested against it strongly, but he was obdurate. And I am compelled to do it before I have had my breakfast,” hollowly. “It is scarcely short of barbarous.”
Here the small horse stretched its neck and shook itself until the harness rattled. Pendleton looking from master to beast thought they might exchange places much to the master’s ultimate well-being.
There was a short pause; then Dr. Mercer bent his head toward them.
“When you visited the institute a few nights ago,” said he, “you also, at my request, visited Professor Locke.”
Ashton-Kirk nodded.
“For some time,” proceeded the other, “I have fancied that there was something wrong with him. Not of a physical nature, as is, unfortunately the case with myself, but more in a mental way. But since that night I have been sure that some sort of a derangement had fixed itself upon him, or is in progress. He can scarcely be called the same person. More than once I have been afraid,” and here the speaker lowered his voice to a husky whisper, “that he is unbalanced.”
“That is very grave,” said Ashton-Kirk.
“It has occurred to me,” went on the doctor, not without shrewdness, “that something happened that night which unsettled him.” The eyes seemingly floating in fat, turned themselves first to Pendleton, then to Ashton-Kirk. “I suppose, though, you know nothing of it?”
“We noticed that he seemed greatly agitated,” replied the investigator. “And we are alarmed to hear that he seems disturbed.”
“It is our rule that no one leave the institute grounds after nightfall,” said Dr. Mercer, in a troubled voice. “Last night I had occasion to send for him, but he was gone. This morning I stopped to reproach him for his absence; but apparently he has not returned.”
“You’re mistaken there,” put in Burgess. “Look!”
He indicated the house as he spoke. The small figure of Locke was seen emerging at the front door; he paused for a moment, peering this way and that in his nearsighted fashion, then hastily made his way toward the workshop. Evidently he had not seen them.
With great labor and much catching of breath Dr. Mercer had turned sufficiently to see these things. He seemed greatly astonished.
“He was there all the time,” said he. “It is not possible that he did not feel the vibrations of the buzzer, for he is very sensitive to such things.”
His indignation appeared to swell him to even greater proportions than before.
“It is an affront,” he stated in a choked tone. “It is a deliberate affront. He felt the buzzer, and he knew it was I. But he did not consider me of enough importance to trouble himself about.”
Panting he sought to turn the small horse, but in a moment Ashton-Kirk was out in the road and had the animal by the head.
“I beg your pardon,” said the investigator, “but it would probably be more beneficial to yourself and others, if you continued your drive and left Professor Locke to us.”
Amazed beyond ability to stir, the doctor sat and stared. But finally he found his tongue.
“Bless my soul and body,” exclaimed he with a great wheezing exhalation. “I scarcely understand this, sir.”
“My dear doctor,” said Ashton-Kirk soothingly, “it is not at all necessary that you do so. The fact is, to state it briefly, there is a trifling matter for adjustment between Professor Locke and the commonwealth.”
“The commonwealth!” cried the doctor, and he shook like a great mass of gelatine.
“Nothing less. So, you see, it will be as well for you to do as I suggest.” Then turning to Pendleton, Ashton-Kirk continued: “I think we had better walk the remainder of the way; otherwise we might get Locke’s attention before it is advisable.”
Pendleton jumped down, and without another word to Dr. Mercer, they set off toward the slate-roofed house by the roadside. However, after they had gone about fifty yards, Pendleton turned and looked back. He saw the small horse jogging away, while behind it, helplessly fat and hopelessly befogged, sat Dr. Mercer, swaying dispiritedly from side to side.
As Ashton-Kirk and Pendleton advanced upon the house, they bore in mind the possibility of Locke being on the watch; so they kept out of sight as much as possible.
“It’s rather odd, I think, that he hangs on here, knowing that his part in the murder of Hume must now be known,” said Pendleton. “I rather expected an attempt at escape.”
“That may come later,” said the investigator, grimly. “The finish of a thing of this sort is always a matter for speculation. I have seen desperate criminals who surrendered like lambs; and I’ve seen the
