"That's it!" cried Bahama Bill, in delight. "I knew it must be around here somewhere—but what made that big rock tumble down?"

"Maybe somepody pushed him ofer," said Hans.

"Four men couldn't budge that rock," declared Fred.

"I believe an earthquake must have done it," came from Anderson Rover, and suddenly his face grew grave. "I trust no earthquake has disturbed the treasure cave," he added.

They pushed on, but scarcely had they covered a quarter of a mile when Bahama Bill called another halt. And well he might, for the trail they had been following came to an abrupt end in front of a pit several rods in diameter and twenty to thirty feet deep. The bottom of the pit was choked up with rocks, dead trees and brushwood.

"What now?" asked Mr. Rover, and his tone betrayed his uneasiness.

"This wasn't here afore," said the old tar, briefly. He was so "stumped" he could scarcely speak.

"You are sure?"

"Dead certain."

"Then this isle has undoubtedly been visited by an earthquake within the last few years."