“I guess they’ve all gone,” said Fenn. “There don’t seem to be any of the miners here, now.”

Hardly had he spoken when, turning a corner in the shaft, the party came upon a curious scene. In a big chamber, the same one which Fenn had viewed from the crack in the door of his small prison, there were half a score of men, working by the light of torches, digging stuff from the walls of the cave, and carrying it out in small boxes.

“Here they are!” shouted Fenn. “This is the place, and they’re at work!”

“To the shaft!” shouted some one. “They’re after us!”

There was a hurrying and scurrying to escape, and, before the detectives or Mr. Hayward could make any move to capture the men, they had all disappeared.

“Come on!” cried Mr. Harkness. “Show us the way to the shaft where the ladder is, Fenn! Maybe we can nab some of ’em.”

“It isn’t worth while,” declared Mr. Hayward. “These men were evidently afraid of being caught, but, from what I can see, they were not doing anything unlawful.”

“No,” admitted Mr. Harkness. “We caught the last of them when we got Lem Sing. But what were these men digging?”

“I’ll take a look,” answered Robert Hayward.

Suddenly he gave a cry, as he took some of the soft earth in his fingers.