"I really don't know. I should think so."
"Will you please have Miss Barton, or someone else, find those stockings and see if all the pairs like this are complete," instructed The Thinking Machine.
Wonderingly, Mrs. Blake gave the order to Miss Barton, who as wonderingly received it and went out of the room with a quick, resentful look at the bowed figure of the scientist.
"Did you ever happen to notice, Mrs. Blake, whether or not your baby could open a door? For instance, the front door?"
"I believe he could," she replied. "He could reach them because the handles are low, as you see," and she indicated the knob on the front door, which was visible through the reception hall room where they stood.
The Thinking Machine turned suddenly and strode to the window of the library, looking out on the back yard. He was debating something in his own mind. It was whether or not he should tell this mother his fear of her son's death, or should hide it from her until such time as it would appear itself. For some reason known only to himself he considered the child's death not only a possibility, but a probability.
Whatever might have resulted from this mental debate was not to be known then, for suddenly, as he stood staring out the rear window overlooking the spot where the baby's tracks had been seen in the snow-now melted-he started a little and peered eagerly out. It was the first sight he had had of the yard since the night he had examined it by moonlight.
"Dear me, dear me," he exclaimed suddenly.
Turning abruptly he left the room, and a moment later Hatch saw him in the back yard. Mrs. Blake at the window watched curiously. Outside The Thinking Machine walked straight out to the spot where the baby's tracks had been, and from there Hatch saw him stop and stare at the slightly raised box which covered the water connections.
From this box the scientist took five steps toward a flat-topped stone-the one he had noticed previously-and Hatch saw that it was about ten feet. Then from this he saw The Thinking Machine take four steps to where the sagging clothes-line hung. It was probably eight feet. Then the bowed figure of The Thinking Machine walked on out toward the rear wall of the enclosure, under the clothes-line.
When he stopped at the end of the line he was within fifteen feet of the dangling swing which had been Baby Blake's. This swing was attached to a limb twenty feet above-a stout limb which jutted straight out from the tree trunk for fifteen feet. The Thinking Machine studied this for a moment, then passed on beyond the tree, still looking up, until he disappeared.
Fifteen minutes later he returned to the library where Mrs. Blake awaited him. There was a question in Hatch's eyes.
"I've got it," snapped The Thinking Machine, much as if there had been a denial. "I've got it."
V.
On the following day, by direction of The Thinking Machine, Mrs. Blake ordered the following advertisement inserted in all Boston and Lynn newspapers, to occupy one-quarter of a page.
TO THE PERSONS WHO NOW.
HOLD DOUGLAS BLAKE:.
"Your names, residence and place of concealment of Douglas Blake, fourteen months old, and the manner in which he came into your possession are now known.
"Mrs. Blake, the mother, does not desire to prosecute for reasons you know, and will give you twenty-four hours in which to return the baby safely to its home in Lynn.
"Any attempt to escape of either person concerned will be followed instantly by arrest. Meanwhile you are closely watched, and will be for twenty-four hours, at which time arrest and prosecution will follow.
"No questions will he asked when the child is returned and your names will be fully protected. There will also be a reward of $1,000 for the person who returns the baby."
Hutchinson Hatch read this when The Thinking Machine had completed it and had stared at the scientist in wonderment.
"Is it true?" he asked.
"I am afraid the child is dead," repeated The Thinking Machine evasively. "I am very much afraid of it."
"What gives you that impression?" Hatch asked.
"I know now how the child was taken from that back yard, if we grant that the child itself made the tracks," was the rejoinder. "And knowing how it was taken away makes me more fearful than I have been that it is not alive; in fact, that it may never be seen again."
"How did the child leave the yard?"
"If the child does not appear within twenty-four hours," was the reply, "I shall tell you. It is a hideous story."
Hatch had to be content with that statement of the case for the moment. None knew better than he how useless it would be to question The Thinking Machine.
"Did you happen to know, Mr. Hatch," The Thinking Machine asked, "that in the event of the death of Douglas Blake, his fortune of nearly three million dollars left in trust by his father would be divided among four relatives of Mrs. Blake?"
"What?" asked Hatch, a little startled.
"Suppose for instance, Baby Blake was never found, as seems possible," went on the other. "After a certain number of years, I believe, in a case of that kind there is an assumption of death and property passes to heirs. You see then, there was a motive, and a strong one, underlying this entire affair."
"But, surely there wouldn't be murder?"
"Not murder," responded The Thinking Machine tartly. "I haven't even suggested murder. I said I believe the child is dead. If it is not dead who would benefit by his disappearance? The four whom I named. Well, suppose Baby Blake fell into the hands of those people. It would be comparatively an easy matter for them to lose it in some way-not necessarily kill it-have it adopted in some orphan asylum, place it anywhere to hide its identity. That's the main thing."
Hatch began to see light faintly, he thought.
"Then this advertisement is to the people who may be holding the child now?" he asked.
"It is so addressed," was the other's reply.
"But, but--" Hatch began.
"Once upon a time a noted wit, who was of necessity a student of human nature," The Thinking Machine began, "declared there was one thing carefully hidden in every man's life which would ruin him should it be known, or land him in prison. He volunteered to prove this, taking any man whose name was suggested. An eminent minister of the gospel was named as the victim. The wit sent a telegram to the minister, who was attending a banquet: 'All is discovered. Flee while there is opportunity,' signed 'Friend.' The minister read it, arose and left the room, and from that day to this he has never been seen again."
Hatch laughed, and The Thinking Machine glanced at him with an annoyed expression on his face.
"I had no intention of arousing your laughter," he said sharply. "I merely intended to illustrate the possible effect of a guilty conscience."
When the flaming advertisement in the newspapers was called to the attention of the police, they were first surprised, then amused. Then they grew serious. After a while an officer went to Mrs. Blake and asked what it meant. She informed him that she had acted at the suggestion of Professor Van Dusen. Then the police were amused again; they are wont to feign an amusement which they never feel in the presence of a superior mind.
That afternoon, Hatch, who by direction of The Thinking Machine, was on watch again near the Blake home, received a strange request from the scientist by telephone. It was:
"Go to the Blake home immediately, see the picture book which Baby Blake was looking at just before his disappearance, and report to me by 'phone just what's in it."
"The picture book?" Hatch repeated.
"Certainly, the picture book," said the scientist, irritably. "Also find out for me from the nurse and Mrs. Blake if the baby cried easily, that is from a slight hurt or anything of that kind."
With these things in his mind Hatch went to the Blake house, had a look at the picture book, asked the questions as to Baby Blake's propensity to weep on slight provocation, and returned to the 'phone. Feeling singularly foolish, he enumerated to The Thinking Machine the things he had seen in the picture book.
"There's a horse, and a cat with three kittens," he explained. "Also a pale purple rhinoceros, and a dog, an elephant, a deer, an alligator, a monkey, three chicks, and a whole lot of birds."
"Any eagle?" queried the other.
"Yes, an eagle among them, with a rabbit in its claws."