It was solid--not a crevice or a break through which might have travelled the sound of his voice or the explosion of a gun.

He did not shout.

He knew that it would be hopeless, and that his voice would be terrifying in that sepulchral tomb.

Was it possible that there might be some other opening--a possible exit--in that mountain wall?
With the lantern in his hand he searched.

There was no break.