He advanced to the door, and having first rapped with his knuckles and then kicked at it vigorously, tried the handle.
"Locked," he observed, "but I see the key is in the lock, so we can get in if we want to. Let us try the back."
The back door was locked, too, but the key had been removed.
"He came out this way, evidently," said Thorndyke, "though he went in at the front, as I suppose you noticed. Let us see where he went."
The back garden was a small, fenced patch of ground, with an earth path leading down to the back gate. A little way beyond the gate was a small barn or outhouse.
"We are in luck," Thorndyke remarked, with a glance at the path. "Yesterday's rain has cleared away all old footprints, and prepared the surface for new ones. You see there are three sets of excellent impressions—two leading away from the house, and one set towards it. Now, you notice that both of the sets leading from the house are characterized by deep impressions and short steps, while the set leading to the house has lighter impressions and longer steps. The obvious inference is that he went down the path with a heavy burden, came back empty-handed, and went down again—and finally—with another heavy burden. You observe, too, that he walked with his stick on each occasion."
By this time we had reached the bottom of the garden. Opening the gate, we followed the tracks towards the outhouse, which stood beside a cart-track; but as we came round the corner we both stopped short and looked at one another. On the soft earth were the very distinct impressions of the tyres of a motor-car leading from the wide door of the outhouse. Finding that the door was unfastened, Thorndyke opened it, and looked in, to satisfy himself that the place was empty. Then he fell to studying the tracks.
"The course of events is pretty plain," he observed. "First the fellow brought down his luggage, started the engine, and got the car out—you can see where it stood, both by the little pool of oil, and by the widening and blurring of the wheel-tracks from the vibration of the free engine; then he went back and fetched the boy—carried him pick-a-back, I should say, judging by the depth of the toe-marks in the last set of footprints. That was a tactical mistake. He should have taken the boy straight into the shed."
He pointed as he spoke to one of the footprints beside the wheel-tracks, from the toe of which projected a small segment of the print of a little rubber heel.
We now made our way back to the house, where we found Willett pensively rapping at the front door with a cycle-spanner. Thorndyke took a last glance, with his hand in his pocket, at an open window above, and then, to the coachman's intense delight, brought forth what looked uncommonly like a small bunch of skeleton keys. One of these he inserted into the keyhole, and as he gave it a turn, the lock clicked, and the door stood open.
The little sitting-room, which we now entered, was furnished with the barest necessaries. Its centre was occupied by an oilcloth-covered table, on which I observed with surprise a dismembered "Bee" clock (the works of which had been taken apart with a tin-opener that lay beside them) and a box-wood bird-call. At these objects Thorndyke glanced and nodded, as though they fitted into some theory that he had formed; examined carefully the oilcloth around the litter of wheels and pinions, and then proceeded on a tour of inspection round the room, peering inquisitively into the kitchen and store-cupboard.
"Nothing very distinctive or personal here," he remarked. "Let us go upstairs."
There were three bedrooms on the upper floor, of which two were evidently disused, though the windows were wide open. The third bedroom showed manifest traces of occupation, though it was as bare as the others, for the water still stood in the wash-hand basin, and the bed was unmade. To the latter Thorndyke advanced, and, having turned back the bedclothes, examined the interior attentively, especially at the foot and the pillow. The latter was soiled—not to say grimy—though the rest of the bed-linen was quite clean.
"Hair-dye," remarked Thorndyke, noting my glance at it; then he turned and looked out of the open window. "Can you see the place where Miss Haldean was sitting to sketch?" he asked.
"Yes," I replied; "there is the place well in view, and you can see right up the road. I had no idea this house stood so high. From the three upper windows you can see all over the country excepting through the wood."
"Yes," Thorndyke rejoined, "and he has probably been in the habit of keeping watch up here with a telescope or a pair of field-glasses. Well, there is not much of interest in this room. He kept his effects in a cabin trunk which stood there under the window. He shaved this morning. He has a white beard, to judge by the stubble on the shaving-paper, and that is all. Wait, though. There is a key hanging on that nail. He must have overlooked that, for it evidently does not belong to this house. It is an ordinary town latchkey."
He took the key down, and having laid a sheet of notepaper, from his pocket, on the dressing-table, produced a pin, with which he began carefully to probe the interior of the key-barrel. Presently there came forth, with much coaxing, a large ball of grey fluff, which Thorndyke folded up in the paper with infinite care.
"I suppose we mustn't take away the key," he said, "but I think we will take a wax mould of it."
He hurried downstairs, and, unstrapping the case from his bicycle, brought it in and placed it on the table. As it was now getting dark, he detached the powerful acetylene lamp from his machine, and, having lighted it, proceeded to open the mysterious case. First he took from it a small insufflator, or powder-blower, with which he blew a cloud of light yellow powder over the table around the remains of the clock. The powder settled on the table in an even coating, but when he blew at it smartly with his breath, it cleared off, leaving, however, a number of smeary impressions which stood out in strong yellow against the black oilcloth. To one of these impressions he pointed significantly. It was the print of a child's hand.
He next produced a small, portable microscope and some glass slides and cover-slips, and having opened the paper and tipped the ball of fluff from the key-barrel on to a slide, set to work with a pair of mounted needles to tease it out into its component parts. Then he turned the light of the lamp on to the microscope mirror and proceeded to examine the specimen.
"A curious and instructive assortment this, Jervis," he remarked, with his eye at the microscope: "woollen fibres—no cotton or linen; he is careful of his health to have woollen pockets—and two hairs; very curious ones, too. Just look at them, and observe the root bulbs."
I applied my eye to the microscope, and saw, among other things, two hairs—originally white, but encrusted with a black, opaque, glistening stain. The root bulbs, I noticed, were shrivelled and atrophied.
"But how on earth," I exclaimed, "did the hairs get into his pocket?"
"I think the hairs themselves answer that question," he replied, "when considered with the other curios. The stain is obviously lead sulphide; but what else do you see?"
"I see some particles of metal—a white metal apparently—and a number of fragments of woody fibre and starch granules, but I don't recognize the starch. It is not wheat-starch, nor rice, nor potato. Do you make out what it is?"
Thorndyke chuckled. "Experientia does it," said he. "You will have, Jervis, to study the minute properties of dust and dirt. Their evidential value is immense. Let us have another look at that starch; it is all alike, I suppose."
It was; and Thorndyke had just ascertained the fact when the door burst open and Mrs. Haldean entered the room, followed by Mrs. Hanshaw and the police inspector. The former lady regarded my colleague with a glance of extreme disfavour.
"We heard that you had come here, sir," said she, "and we supposed you were engaged in searching for my poor child. But it seems we were mistaken, since we find you here amusing yourselves fiddling with these nonsensical instruments."
"Perhaps, Mabel," said Mrs. Hanshaw stiffly, "it would be wiser, and infinitely more polite, to ask if Dr. Thorndyke has any news for us."
"That