"I see nothing but a blank wall twenty feet away," he called down. "And not much of that. It looks like the wall of the rift. I tell you what: this room must be cut out of the wall this side. When you called it a castle, you spoke better than you knew, Mac."
"Ay, so it seems," Mackenzie replied, as Forrester sprang down. "But I'm fair flummoxed. The room's perfectly light, though yon slit isn't more than twelve by two. Where does the light come from? It's greenish, too, which accounts for our delicate complexions. And look! you see that?"
He pointed to the faint shadow of a fourth human figure that passed across the wall opposite to the window. It flitted through their own shadows, and disappeared.
A moment's glance assured them that it had not been cast from without; yet the wall appeared solid, in no degree transparent.
There was no furniture in the room. Silently they sat upon the floor, watching the wall nervously for a return of the mysterious inexplicable shadow. But it did not reappear. The strange light, the stranger apparition, brought back upon them redoubled the uneasiness they had felt ever since they entered the rift, and especially after seeing the ghostly procession on the wall. At that moment they could have believed that they lay in the haunt of some necromancer, whose magic art might manifest itself in terrors unconceived.
"They must have hocussed us," murmured Forrester at length, his thoughts reverting to his last conscious moments in the rift.
"Ay, put us to sleep with some narcotic gas," said Mackenzie. "What'll they do next?"
"What have they done with our men?" said Jackson.
"Separated the goats from the sheep," replied Mackenzie sardonically. "They are evidently respecters of persons!"
"But----"