Lyall arrived

suddenly he stiffened. The little disc had blazed to light .

"Ah! our visitor is at the garden gate," he said gently . He folded his arms on the desk and his head lolled forward. To all appearances, Valmon Dain had fallen asleep in his chair. But one eye steady and unwinking, stared at the little box on the table waiting for the white light to flash out, telling him that Willard Lyall was at the laboratory door.

A face peered in at the window, a face that slid cautiously inch by inch into full view behind the glass. It was Lyall. There was a frown of disappointment on his forehead ; he had not expected to find Dain still up.

But the frown gave way to a slow smile of satisfaction when he saw all that was in the room. Fate seemed to have played Dain right into his hands.

With a quick All-embracing look, he inspected the interior of the workshop.

The face moved from the window, and for a tense, long-drawn-out minutes there was a silence in the great laboratory. a silence that seemed to hang in the air like something tangible.

Dain sprawled on his desk as motionless as a statue, his head in his arms. one eye fixed without a flick on the white disc in the tiny box.

There was no direct entrance from the garden into the workshop. The only door in the whole room was the one that communicated with the house. the one in the left hand wall away from the desk. Anybody coming into that room would have to come in either through that or through the window. which in any case was set a little high to present an easy means of access.

Dain was relying on an entry through the door. he hadn't seen the grim apparition at the window. All he knew was that someone had come in through the garden gate.

From outside the door came the faint sound of a creaking floorboard, so slight as to be scarcely audible. A moment later the white light snapped into life, and the quiet purring murmur began in the opposite wall. Somebody had touched the door.

The noticeableness of the humming in the utter stillness worried Dain. He hadn't bargain for it. But with a quick deft movement of the arm he reached over to the wall against his right hand and switched over a little brass knob. The action started an electric fan into motion, a small one high up against the ceiling on the far end wall. it, too, worked almost without sound but such slight noise as it did make was sufficient to tone out the queer purring coming from just underneath it. In a second he was back in his old attitude, his head resting wearily on his arms, his respiration coming and going with the peaceful regularity of a man in a deep sleep.

Slowly the door opened. There was no sound, not even the soft click of the lock. Inch by inch it opened until the aperture was wide enough to admit the passage of a man.

Lyall came in, stared hard at Dain and began closing the door. Then as silent as the shadow of a ghost, he tiptoed towards Dain's desk. Halfway across Dain, Dain stirred slightly and the moving figure stopped as stiff as a frozen rabbit, staring with rabid intensity at the man in the chair.

Dain muttered something inaudible in an apparently trouble sleep, and then relapsed into tired inertia again..

Lyall crept on foot by foot over the soft rug till he was within grasping distance of the gun. His hand went out to it silently and as steady as a rock. In spite of the dreadful thing he intended doing, there was not the slightest trace of a reaction on his nerves. The hand going out to the gun might have been of white marble.

The fingers closed over the weapon slowly, almost lovingly and he picked it up.

Dain lay without moving. He might have been oblivious of even his own existence, so log-like was his simulation of sleep.

Lyall's keen eyes glanced around the room. A revolver shot would make a bit of noise, and he wanted to see that the way of escape was open and easy of access. The window looked about the likeliest exit. It would mean getting up on to the bench, but he could do that without interfering with any of the paraphernalia. He could open that window, slip out and close it behind him in something under thirty seconds. And it was hardly possible that any of the servants could get down to the laboratory from the top of the house in thirty seconds, even if they heard the firing of the shot.

Then his eyes chanced on Dain's rubber gloves lying on the bench, where he had tossed them and put them on. Rubber gloves eliminate finger-marks and Lyall preened himself on a stroke of luck.

He went over to the window and scrutinized it closely. Nothing very difficult there just the ordinary catch screwed into the woodwork. He pulled the catch back and raise the window a couple of inches, all ready to slip it up quickly and jump out.

Outside, a church clock struck midnight. Twelve ponderously brassy strokes that clanged sonorously through the darkness and the thought sped through Lyall's brain: "Five minutes after midnight Valmon Dain will be a dead man."

He walked back the desk, unmindful of any sound he might have made. There was no need now for silence. His gun was pointing dead at Dain's heart.

"Valmon Dain," he said grimly, "wake up."