The Patterson Blake Box Set: Books 1 & 2, and 3

Patterson Blake is an FBI Agent on a mission. When she was a teenager, her older sister vanished while on a cross-country road trip and hasn't been seen since. Patterson thought she'd put the trauma of her sister's disappearance behind her, but now there is new evidence, and suddenly the old wounds reopen. Except that Patterson isn't a kid anymore. She has a badge and a gun, and the resources to follow her sister's trail. But it won't be as easy as Patterson thinks. There are dangers lurking along the way, and solving her sister's case will thrust Patterson into a mystery deeper than she could have ever imagined, and might even cost the tenacious FBI Special Agent her life…

Book 1 - Sister Where Are You
Book 2 - Is She Really Gone
Book 3 - All The Dead Girls