“I’ll bet anything that those Black Riders had shells like that and maybe all that stuff about the camp being haunted is true,” argued Plum. “It sort of seems as though a spirit of one of those fellows is trying to warn us away!”

“Do you believe in ghosts, Plum?” Ted asked, looking straight into the eyes of the big boy.

“Well, no, but——”

“If this was a ghost he was a pretty careless one wasn’t he? Couldn’t even hold on to his conch. I guess we don’t have to worry about anyone as careless as that.”

Plum muttered but no further attention was paid to him. They hunted all around the rock and even went a short distance into the surrounding woods, but not a single clue was to be found. The woods were dark and silent, breathing an air of mystery.

Ted ordered them back to the camp and to bed. There was a bit of protest at this, but Ted put it down at once.

“There is no need to sit up and talk about it all,” he told them. “It is already past the hour for retiring anyway, and you need sleep, because some of you didn’t sleep any too well last night. I guess everything is over and you’ll have nothing to worry about.”

“You guess!” grumbled Plum, expressively.

Ted looked at him sternly. “We’re not going to sit up like a bunch of frightened old maids looking for something to happen,” he said. “Into your tents, now!”

There was much chattering as the boys reluctantly obeyed this order. Buck and Ted met for a final word.