What strange places they came upon in this underground region below the ill-famed house!  Plainly these cells had been built once for prisoners; for there were fragments of rusty chains still fastened to the stone floors, and in one spot a grinning skull lying broken in a corner sent thrills of horror through the brothers’ hearts.  From time to time the sound of that unearthly wailing reached their ears, though it was almost impossible to divine from what direction it proceeded; and it had a far less human sound now that the boys were within the precincts of the house than had been the case when they were still outside.

Whether this was more alarming or less they hardly knew.  Everything was so strange and dreamlike that they could not tell whether or not all were real.  They pressed on eager to accomplish the object of their search, resolved to do that at all cost, and anxious to keep themselves from thinking or feeling too much until that object should be accomplished.

They had mounted some stairs, and had reached a different level from the underground passages, when they found their further progress barred by a strong door.  This door was bolted, but from the outside, and they had no difficulty in withdrawing the heavy bolts from their sockets.  When this had been done the door opened of itself, and they found themselves in a large vaulted room utterly unlike any place they had ever seen before.  They grasped each other by the hand and gazed about in wonder.

“It is the magician’s laboratory!” whispered Raymond, whose recent readings with John had taught him many things.

He recognized the many crucibles and the strange implements lying on the table as the things employed by dabblers in magic lore, whilst the great sullen wood and charcoal fire, which illumined the place with a dull red glow, was all in keeping with the nature of the occupations carried on there, as was the strange pungent smell that filled the air.

Rows of jars and bottles upon shelves, strange-looking mirrors and crystals, some fixed and some lying upon the tables, books and parchments full of cabalistic signs propped open beside the crucibles or hung against the wall, all gave evidence of the nature of the pursuits carried on in that unhallowed spot.  The brothers, burning with curiosity as well as filled with awe, approached the tables and looked into the many vessels lying upon them, shuddering as the crimson contents made them think of blood.

Gaston put forth his hand cautiously and touched an ebony rod tipped with crystal that lay beside the largest crucible.  As he did so a heavy groan seemed to arise from the very ground at his feet, and he dropped the implement with a smothered exclamation of terror.  Raymond at the same moment looking hastily round the dim place, grasped his brother’s arm, and pointed to a dark corner not many paces from them.

“Brother, see there! see there!” he whispered.  “Sure there is the boy we have come to save!”