"Great heavens! It's Lew Grandall!" cried the stranger on the raft. (Page 399) THEAUTO BOYS'MYSTERY By JAMES A. BRADEN AUTHOR OF "THE AUTO BOYS," "THE AUTO BOYS' ADVENTURE," "THE AUTO BOYS' CAMP," "THE AUTO BOYS' BIG SIX," "FAR PAST THE FRONTIER," ETC. FRONTISPIECE BY ALFRED RUSSELL THE SAALFIELD PUBLISHING COMPANYCHICAGO AKRON, OHIO NEW YORK THE AUTO BOYS' MYSTERY 1CHAPTER IPROLOGUE 1 PROLOGUE The Auto Boys had been camped on the unfrequented shore of Opal Lake for several days. At first hunting and fishing were the only enlivening features of this, their unusual summer outing. Opal Lake, far up in the big northern woods, had at this time no other campers. True, there was an abandoned clubhouse on a nearby point not far from where Phil Way, Billy Worth, Dave MacLester and Paul Jones selected the spot for their Outing Camp. But, until within a day or two, even the clubhouse had seemed to be as it looked, deserted. But a smoke being seen one day, the boys had 2 become curious. Without actually entering the house itself, they had made individual or collective trips that way. Also strange sounds had been heard, and even human presence had been detected. Finally Paul, the youngest of the boys, made a cautious trip thither and even entered the house where he had heard voices, and otherwise had detected that real folks were undoubtedly there; though why they were there Paul could only guess. Perhaps they were in search of a bag of money, said to be twenty thousand dollars, stolen three years before and supposed still to be hidden somewhere in that region. 2 Strange men had been seen