“Let’s see,” he mused. “‘0’ could be either C, M or W; and ‘2’ might be E, O or Y. Number 6 would have to be I or S. Number 1 could represent D, N or X. And 4 would have to be G—”
Dan went no further, for suddenly he saw that the puzzle actually was beginning to make sense. Excitedly he wrote in the first combination of letters:
020614
COMING
“Yipee! I’ve got it!” he muttered. “I’ve found the key!”
A strong gust of wind unexpectedly flapped the light canvas which hung across the cave doorway.
So engrossed was Dan that he did not notice. Nor did he see a shadowy figure crouching on the platform.
Then the light suddenly was extinguished. Startled, Dan jerked to attention.
As he groped for a match with which to relight the lamp, a deep voice entoned:
“Take warning, Dan Carter! Remain away from Skeleton Island!”
Dan felt the hair rise on his neck. Chills slithered down his spine. The mysterious voice, he realized, came from the cave entranceway.