Strange things have been happening at Windy Rafters resort. Mellie Stevens is indignant that the shadow of blame falls repeatedly on herself, her sister, and their younger cousins. To clear their names, the six cousins organize themselves as the Windy Rafters Roughnecks.

Working out of the old treehouse in the farmyard, the Ferris cousins investigate suspects and, in the process, make some unlikely friends, and discover some great neighbours.

Just when they think they have the mystery solved, the younger kids are transported back in time to the days before their family owned the Windy Rafters land. Both the Blackfoot people the younger cousins meet and their experiences in the past will prove invaluable when a big Californian company offers to buy out the resort and solve the family's money problems for good.