Rizzoli & Isles may have made their name with a hit drama on TNT, but their best work is found between the pages of Tess Gerritsen’s terrific thriller series. The novelization almost always beats the big or small screen treatment, and this series is no exception. Whereas the TV show took time to be quirky and got deeper into the lives of a host of secondary characters, the books focus on the crimes and the horror they bring. Gerritsen is at the top of her game with I KNOW A SECRET, her latest Rizzoli & Isles novel.

In the Acknowledgements, Gerritsen thanks her mother, an immigrant from China with a shaky handle on the English language. One thing she did have an affinity for were horror movies and shared this love with her daughter. Gerritsen references classic films like Invasion of the Body Snatchers,Them andThe Thing, and mentions working on her own independent horror flick, Island Zero. It is no coincidence that an indie horror movie is a key element in I KNOW A SECRET.

"[T]wist after unexpected twist will find even the most astute mystery/thriller reader reeling, as I was, and the final sentence will haunt you long after you close the cover of this superior work."

The book begins with a discussion of human monsters. This is the thought running through the mind of Dr. Maura Isles as she looks at the cancer-riddled body of a woman she only found out a few years earlier was her mother. She also learned that Amalthea Lank was a murderer, a serial killer who earned her life in prison --- a life that was probably just days away from ending. As Maura is still trying to come to terms with this relationship, Amalthea claims that their entire family has profited from the dead, and Maura, as a medical examiner for the Boston PD, has made her own career by doing the same thing.

There is another monster at work here. When a series of gruesome murders hit the area, the case is led by Detective Jane Rizzoli. With a body count at two that includes different forms of mutilation, it is feared that a pattern killer is on the prowl. As the investigative team begins looking at the two murders for similarities, some startling connections begin to emerge. The first is the appearance of a strange woman at the funeral of each of the murder victims. Next is a theory that the murders may be tied to some sort of religious ritual with each kill being set up to represent the death of various saints.

There is another similarity, and it will take the case in a whole new direction. The two murder victims had been involved in their childhood with an infamous case of murder and child abuse that took place at the Apple Tree Daycare Center. Its owners --- a father, mother and son --- were all tried and found guilty of child abuse. They were also accused of worse in the disappearance of a young girl whose body was never found. The hat she was wearing was later discovered on the school bus driven by the son, Martin Stanek. The elder Staneks died in prison, while Martin, decades later, has just been released. Is he seeking vengeance against the children whose testimony put him and his family behind bars?

When a third victim is discovered and is also tied to Apple Tree Daycare, Rizzoli and her team put all their efforts into the remaining child whose initial testimony started the entire case years earlier --- a young woman named Holly Devine. They keep Holly under surveillance, and during a sting operation at a bar, they apprehend a woman who approaches Holly in a suspicious way. It turns out this stranger is Bonnie Sandridge, a journalist who is writing a novel in which the Staneks play a central role. When it is learned that Bonnie may be harboring Martin, there is no doubt that Rizzoli and company need to take them down.

However, knowing that this is a Tess Gerritsen novel should alert readers to the fact that things may not be wrapped up quite so neatly. I do not want to go any further for fear of revealing spoilers. Ironically, many of the answers to I KNOW A SECRET may be found inside the independent feature Mr. Simian that one of the murder victims had been working on. Much of the symbolism inside that film describe the truth behind the Apple Tree Daycare case. Let me just say that twist after unexpected twist will find even the most astute mystery/thriller reader reeling, as I was, and the final sentence will haunt you long after you close the cover of this superior work.