"Now look here!" whispered the landlord. "D'ye see that one window with the whitish blind and the light behind it? I came up here, maybe half an hour ago, to see if we were out of something that's kept here, and I chanced to look out on to Joseph Chestermarke's garden. Mr. Neale!—there's a man in that room with the light-coloured blind—I saw his shadow on the blind, pass and repass, you understand, twice, while I looked. And—it's not Joseph Chestermarke!"

"Could you tell?—had you any idea?—whose shadow it was?" demanded Neale eagerly.

"No!—he passed in a sort of slanting direction—back and forward—just once," answered Walford. "But—his build was, I should say, about the like of John Horbury's. Mr. Neale—Horbury might be locked up there! He's a bad 'un, is Joe Chestermarke—oh, he's a rank bad 'un, my lad!—though most folk don't know it. You don't know what mayn't be happening, or what mayn't have happened in yon place! But look here—I can't stop. Me and Sam Barraclough's going off to Wymington now, in his motor—he'll be waiting at this minute. You do what I say—stop here and watch a bit. And if you see aught, go to Polke and insist on the police searching that place. That's my advice!"

"I shall do that, in any case, after what you've said," muttered Neale, who was staring at the lighted window. "But I'll watch here a bit. You've said nothing of this to anybody else?"

"No," replied the landlord. "As I said, I knew you were in the house. Well, I'm off, then. Shan't be back till late tomorrow night—and I hope you'll have some news by then, Mr. Neale."

Walford went off across the creaking floor and down the stairs, and Neale leaned out of the dismantled window and stared into the garden beneath. Was it possible, he wondered, that there was anything in the old fellow's suggestion?—possible that the missing bank manager was really concealed in that mysterious laboratory, or workshop, or whatever the place was, into which Joseph Chestermarke never allowed any person to enter? And if he was there at all, was it with his consent, or against his will, or—what? Was he being kept a prisoner—or was he—hiding?

In spite of his own knowledge of Horbury, and of Betty Fosdyke's assertions of her uncle's absolute innocence, Neale had all along been conscious of a vague, uneasy feeling that, after all, there might be something of an unexplained nature in which the manager had been, or was concerned. It might have something to do with the missing jewels; it might be mixed up with Frederick Hollis's death; it might be that Horbury and Joseph Chestermarke were jointly concerned in—but there he was at a loss, not knowing or being able to speculate on what they could be concerned in. Strange beyond belief it was, nevertheless, that old Rob Walford should think the shadow he had seen to be the missing man's! Supposing——

The door of Joseph Chestermarke's laboratory suddenly opened, letting out a glare of light across the lawn in front. And Joseph came out, carrying a sort of sieve-like arrangement, full of glowing ashes. He went away to some distant part of the garden with his burden; came back, disappeared; re-appeared with more ashes; went again down the garden. And each time he left the door wide open. A sudden notion—which he neglected to think over—flashed into Neale's mind. He left the upper chamber of the old dove-cot, made his way down the stairs to the yard beneath, turned the corner of the buildings, and by the aid of some loose timber which lay piled against it, climbed to the top of Joseph Chestermarke's wall. A moment of hesitation, and then he quietly dropped to the other side, noiselessly, on the soft mould of the border. From behind a screen of laurel bushes he looked out on the laboratory, at close quarters.

Joseph was still coming and going with his sieve—now that Neale saw him at a few yards distance he saw that the junior partner and amateur experimenter was evidently cleaning out his furnace. The place into which he threw the ashes was at the far end of the garden; at least three minutes was occupied in each journey. And—yielding to a sudden impulse—when Joseph made his next excursion and had his back fairly turned, Neale crossed the lawn in half a dozen agile and stealthy strides, and within a few seconds had slipped within the open door and behind it.

A moment later, and he knew he was trapped. Joseph came back—and did not enter. Neale heard him fling the sieve on the gravel. Then the door was pulled to with a metallic bang, from without, and the same action which closed it also cut off the electric light.