"They have gone," he whispered. "In which direction?"
"They had moved off towards the kitchen," said Geoffrey.
"Good! This thing is turning out exactly as I expected. They had something with them?"
"Yes, a thing like a copper octopus with india-rubber tentacles. They have taken it with them. A most extraordinary affair."
"It will be more extraordinary still before it is finished," Ralph said grimly. "Follow them and report what you see. Take good care not to be seen. Unless I am mistaken they are going down to the vaults and are planning a coup to do for us all to-night."
Geoffrey crept silently down the stairs. Then he made his way swiftly along the passages until he came to the cellars. Then the steady blowing of a current of fresh air told him that Ralph's suggestion was right. Down he went until he came to the channel leading to the vaults.
But he was cautious. He peeped down. Below him were three figures, and once more they had spread out their queer apparatus. By the side of it were two large glass-stoppered bottles, such as one sees in a laboratory, receptacles for acids and the like. They were tightly tied over the stoppers.
The woman picked up one of them and removed the parchment. Before she drew the stopper she donned thick glasses and a mask for her face, the two Orientals doing the same. They were evidently dealing with some very dangerous poison.
The stopper was removed and a few spots of the acid dropped on the copper disc. A white smoke arose, which, small as it was, filled the air with a pungent odor. Almost immediately the acid was wiped off and the odor ceased. Only just a whiff of it reached Geoffrey's nose, but it turned him faint—giddy for an instant.
What was going to happen next?