Down in the cellar the Automaton had succeeded in rubbing off the insulation of the feed wires.  There was a flash of light as he laid his steel hand over the two feed wires—­then darkness.

In the dining-room Brent and Flint, already keyed to the highest pitch, leaped to their feet with an exclamation of terror.

Late as it was, Locke was working in his laboratory on the second floor of the house when the lights winked out.  Surprised for the moment, he ran out into the hall.

Already there was the butler, groping about with a candle.

“What’s the matter, Quentin?” asked a breathless voice behind them.

It was Eva in a filmy dressing-gown.  Locke turned to vision a creation of loveliness in the candle-light which set his heart thumping.

“Nothing,” he reassured.  “Just the lights short-circuited, that’s all.  I’ll see.”

Just then the dining-room door opened and Eva saw her father, disheveled and preoccupied, stride out and take the five-branched candlestick from the hall table.  Nervously he began to light the candles.  They sputtered a bit and he turned quickly, still holding the candlestick, as the smoke drifted away from them all.

“Fix the fuses in the cellar,” he directed the butler.

“Is anything—­really the matter—­father?” implored Eva.

“No, no, my child,” he answered, hastily.  “Go back to bed.  And, Locke, please don’t let us be disturbed.”

He was about to say more, then decided not to do so, and turned back into the dining-room.

Again Brent carefully locked the door to the dining-room and rejoined Flint.

He had placed the candles on the table, not noticing in the half-light that the smoke from them was growing denser as they burned down.

The smoke drifted over as the draught carried it.  Flint coughed and moved a bit, his hand at his throat.

Brent seized the pen again and was about to write, when the smoke from the candles drifted into his own face.  He, too, coughed.

Uneasy, Brent glanced over at Flint.  Flint laughed, a bit hysterically.

“What the devil’s the matter?” demanded Brent, with lowered brows, a strange dryness in his throat.

Flint was now leaning forward on his elbows and laughing foolishly, stupidly.  It was a queer laugh, and struck terror into Brent as he himself coughed and clutched involuntarily at his throat.  Brent stared at Flint.

“What is it?” he repeated, anxiously.  “Have you suddenly gone mad, man?”

But there was no reply.  Instead, Flint laughed all the more madly.

Brent was more than startled.  If he could have seen himself in a glass he would have seen that he was already wide-mouthed and disheveled.  Suddenly the smoke again blew in his face.  He coughed again.  His head reeled.

Then, in a flash, it all dawned on him.

He shielded himself from the candles.  But it was too late.