For most people getting hired by a billionaire and paid a huge sum of money to do a job that includes going to sunny Florida via private jet would be a career highlight. Of course, Patrick Kenzie and Angie Gennaro aren't most people so readers of this series know things will go badly. Hell, I'm surprised their plane didn't crash. 
 Patrick and Angie are still recovering from the events in the previous book. Their detective agency is closed for business, and they're spending most of their time 'going to movies, talking in circles, and drinking'. That changes when a dying billionaire insists on hiring them to find his missing daughter. 
 Trevor Stone's wife was killed in a botched car jacking, he was crippled in the attack and then found out that he had a terminal cancer. His daughter, Desiree, had already been grieving because of the drowning death of an old boy friend. She was deeply depressed by all the tragedies around her before she vanished, and he's offering a small fortune to have her found before he dies. 
 The money is nice, but Patrick and Angie have another reason for taking the job. Another detective, Jay Becker, had worked the case, but he also disappeared. Jay is a friend of theirs, and he's also the guy who trained Patrick on detective work. The trail leads to a shady grief counseling group linked to a religious cult, and then to Florida, but things are never what they seem while looking for Desiree and Jay. 
 Lehane had really figured it all out by this third book. In the first book, he let the smart-ass private eye-schtick get a little out of control, but in the second book the dark violence got the upper hand. By Sacred, Lehane has a firm grip on the wheel and a light touch on the accelerator. The book is serious and the violence is grim, but it doesn't overwhelm the story. There's a lot of humor, but it never seems out of place or ruins the tension. The central plot is puzzling, but not frustrating. He also deepens the relationship between Patrick and Angie. 
 Plus, we get a scene with Bubba Rogowski and a blow torch. Who wouldn't want to read that?