He passed his hand across his forehead on which a light sweat stood, though he was not a man easily affected, for he had seen and endured many things.

His mind was very full of strange and troubled thoughts as at last he came back to Bittermeads, where, leaning with his elbows on the garden gate, he stood for a long time, watching the dark and silent house and thinking of that scene of which he had been a spectator when John Clive and the girl had stood together on the veranda in the light of the gas from the hall and had bidden each other good night.

“It seems,” he mused, “as though the last that was seen of poor Charley must have been just like that.  It was just such a dark night as this when Simpson saw him.  He was standing on that veranda when Simpson recognized him by the light of the gas behind, and a girl was bidding him good night—­a very pretty girl, too, Simpson said.”

Silent and immobile he stood there a long time, not so much now as one who watched, but rather as if deep in thought, for his head was bent and supported on his hands and his eyes were fixed on the ground.

“As for this John Clive,” he muttered presently, rousing himself.  “I suppose that must be a coincidence, but it’s queer, and queer the father should have died—­like that.”

He broke off, shuddering slightly, as though at thoughts too awful to be endured, and pushing open the gate, he walked slowly up the gravel path towards the house, round which he began to walk, going very slowly and cautiously and often pausing as if he wished to make as close examination of the place as the darkness would permit.

More by habit than because he thought there was any need of it, he moved always with that extreme and wonderful dexterity of quietness he could assume at will, and as he turned the corner of the building and came behind it, his quick ear, trained by many an emergency to pick out the least unusual sound, caught a faint, continued scratching noise, so faint and low it might well have passed unnoticed.

All at once he understood and realized that some one quite close at hand was stealthily cutting out the glass from one of the panes of a ground-floor window.

CHAPTER IV

A WOMAN WEEPS

Cautiously he glided nearer, moving as noiselessly as any shadow, seeming indeed but one shadow the more in the heavy surrounding darkness.

The persistent scratching noise continued, and Dunn was now so close he could have put out his hand and touched the shoulder of the man who was causing it and who still, intent and busy, had not the least idea of the other’s proximity.

A faint smile touched Dunn’s lips.  The situation seemed not to be without a grim humour, for if one-half of what he suspected were true, one might as sensibly and safely attempt to break into the condemned cell at Pentonville Gaol as into this quiet house.