“Well, we know now that this man Sparewell was alive for at least four years after his disappearance from the Jefferson place, and that he was interested in Cabin Island for some reason, and that he probably made several trips here by boat.”

“Next page!” said Chet, eagerly.

But the next page puzzled them more than ever. There were several lines written, but, so far as the boys could see, they were simply gibberish.

This was what Sparewell had written:

XZYRM. RHOZMW. XSRNMVB. OVUG.

UILMG. MRMV. UVVG. SRTS.

And that was all.

“A cipher message!” Joe exclaimed.

Chet sniffed.

“A lot of good that does us. We can’t make any sense out of that!”