She got up also, but her knees were trembling, and in a moment his hand came out and closed with that official grip upon her elbow.  He led her to the mine entrance guiding her over the rough ground in utter silence.

They left the daylight behind them, passing almost immediately into semi-darkness.  Some rough steps hewn in the rock led down into a black void before them.

“Are there no lights anywhere?” said Dot.

“Yes.  There’ll be a lamp round the corner.  Straight on down!” said Fletcher.

But for his presence she would hardly have dared it, so great was the horror that this place had inspired within her.  But to wait alone with him in that terrible empty valley was even less endurable.  She went down the long, steep stair without further protest.

They reached the foot at length, and a dim light shone ahead of them.  The atmosphere was vault-like and penetratingly damp.  The passage divided almost immediately, and a narrow track led off between black walls of stone to the right, where in the distance another lamp shone.

Fletcher turned towards this, but very suddenly Dot clasped his arm.  “Oh, don’t let us go that way!” she begged.  “Please don’t let us go that way!”

Hill paused in response to her urgent insistence.  “What’s the matter with you, Dot?” he said.

She clung to him desperately, still holding him back.  “I don’t know—­I don’t know!  But don’t go that way!  I have a horrible feeling—­Ah!” The deafening report of a revolver-shot rang out suddenly close to them.

Hill turned with a sound in his throat like the growl of an angry animal, and in a moment he had thrust Dot back against the protecting corner of the wall.

“You are not hurt?” she gasped.

“No; I am not.”  His words fell clipped and stern, though spoken scarcely above a whisper.  “Don’t speak!  Get back up the steps—­as quickly as you can!”

The command was so definite, so peremptory, that she had no thought of disobeying.  But as she moved there came to her the sound of running feet.  Hill stayed her with a gesture.  She saw something gleam in his hand as he did so, and realized that he was not defenceless.

Her heart seemed to spring into her throat.  She stood tense.

Nearer came the feet and nearer.  The suspense of waiting was torture.  She thought it would never end.  Then suddenly, just as she looked to see a man spring from the opening of that narrow passage, they stopped.

A voice spoke.  “All right!  Don’t shoot!” it said, and a great throb of amazement went through her.  That voice—­careless, debonair, half-laughing—­awoke deep echoes in her heart.

A moment later Warden came calmly round the corner, his great figure looming gigantic in that confined space.

He held out his hand.  “I’m sorry you’ve had a fright.  I fired that shot.  It was a signal to the men to line up for inspection.”