As they settle into the cottage on the Overlaar estate for their summer vacation, the four friends — Paul, Roger, Herb and Eddie—look forward to a peaceful summer vacation of swimming, biking, hiking, and taking riding lessons on Skippy, Baron Rensdale’s prize horse.
The first few days, however, bring them slashed tires, a mysterious prowler, and a deliberately set grass-fire. Paul suspects the events to be related, and soon the four friends are scouring the estate for clues. Their search turns up a road map which they had lost on their way to the Overlaar estate and a three-fingered glove.
Their detective work leads to a desperate cross-country chase to rescue their old friend from the three fingered villain.
