It's the middle of the night when Jeff spots someone dumping a large bundle into the lake. It's too dark to identify anyone -- or anything. But the cousins immediately suspect foul play, and plunge right into the mystery. Before they know it, the kids of Cabin Creek are in too deep. Everyone is a suspect -- and the cousins are all in danger.

The cousins try to find out if an old town curse or a kidnapping is behind the disappearance of a bossy boy from the city.

"During summer vacation the cousins are excited to visit their grandparents on Hidden Horse Ranch. They get to sleep in a bunkhouse, swim in a pond with a rope swing, and ride horses any time they want. But they arrive to find that a mysterious fire has destroyed the stables, and the herd has escaped into the nearby canyons. Also troubling, valuable objects have been disappearing from the ranch house. As Jeff, David and Claire follow clues and suspects,...

"During spring break, college student Ariel (from #3, "The Legend of Skull Cliff"), takes the cousins and family friend, Mr. Wellback, camping as her assistants. She has grant money to study wildlife with a drone. But when someone breaks into their tents and steals Claire's diary and David's sketchbook, the cousins feel they're being watched. And when a different drone hovers while they're fishing, the kids set out to investigate who is spying on...