"Why, men!" said Billy, "tha's a chance as how the lad's alive. An that be so no ither body can do for 'im like me w'en he's foond. I wull go doon, I tell ye; I mus' go doon!"

He stepped carefully into the bucket, Conway leaped in after him, and they were lowered away.

At the bottom of the shaft they found no one but the footman, whose duty it was to remain steadily at his post. He listened somewhat incredulously to their hasty explanations, he gave to them another lighted lamp, and wished them good-luck as they started away into the heading.

In spite of his determination and self-will, Bachelor Billy's strength gave out before they had reached the head of the plane, and he was obliged to stop and rest. Indeed, he was compelled often to do this during the remainder of the journey, but he would not listen to any suggestion that he should turn back. The air was still very impure, although they could at times feel the fresh current from the shaft at their backs.

They met no one. The searching parties were all south of the shaft now, this part of the mine having been thoroughly examined.

By the time the two men had reached the foot of Conway's chamber, they were nearly prostrated by the foul air they had been compelled to breathe. Both were still feeble from recent illnesses and were without the power to resist successfully the effects of the poisoned atmosphere. They made their way up the chamber in silence, their limbs unsteady, their heads swimming, their hearts beating violently. At the breast Conway clambered up over the body of the mule and thrust his lighted lamp against the walled-up aperture.

"He's gone through here!" he cried. "He's opened up the hole an' gone through."

The next moment he was tearing away the blocks of slate and coal with both hands. But his fingers were stiff and numb, and the work progressed too slowly. Then he braced himself against the body of the mule, pushed with his feet against Ralph's rude wall, and the next moment it fell back into the old mine. He brushed away the bottom stones and called to his companion.

"Come!" he said, "the way's clear an' we'll find better air in there."

But Bachelor Billy did not respond. He had fallen against the lower face of coal, unconscious. Conway saw that he must do quick work.