It is somewhere there underground.

It seems to me that it is some one who is trying to get out." "Some one underground ?" Jeanne repeated.
Kate leaned over and whispered in her ear.
"There is a passage underneath here," she said, "which goes from the Hall to the cliffs, and a room, or rather a vault." "I know," Jeanne declared suddenly.

"Mr.De la Borne showed it to us.
It was the way the smugglers used to bring their goods up to the cellars of the Red Hall." "We are just above the room here," Kate said slowly, "and I fancy that there is some one there." A sudden light broke in upon Jeanne.
"You think that it is Lord Engleton!" she declared.
"Why not ?" Kate answered.

"Listen again, with your ear close to the ground.

Last night I was almost sure that I heard him call for help." Jeanne did as she was told, and her face grew white as death.
Distinctly between the strokes she heard the sound of a man moaning!.