"Double Fault" by Jerry B Jenkins and Chris Fabry is book number 7 in the Red Rock Mysteries collection. Ashley and Bryce are on another mission to solve another mystery. They signed up for tennis camp at the nearby country club. They discovered that it might be closing for lack of funds, and all of a sudden strange things were going on and the club was losing more money. Someone stole Bryce's ATV and went cruising on the gold course and tore it up. Someone added chemicals to the pool that made it dangerous. Bryce was setup when someone stole from the safe. Is it the local land developer and his son? Is it the high school boys? Someone does not want that country club around anymore and you can bet these twins will get to the bottom of it.