It's a typical farmhouse kitchen. A large table fills the space, and in one of the chairs is the lifeless body of Doctor Magnusson. Under his feet and the dusty wooden floorboards lies the basement – and twelve therapy rooms. Behind each locked door, the victims are about to be rescued...

When a world-renowned psychiatrist is found dead in an abandoned ranch house in the Californian Santa Carina Valley, a Post-it note with the words "Susan Parker" and a cell phone number is taped to the basement door.

Still grieving her husband's devastating suicide less than a year ago, FBI agent Susan Parker is taking a break from work and trying to rebuild her life as a single mom to her seven-year-old daughter, Natalie. When she's called to the crime scene of Doctor Magnusson, a chill runs down her spine.

For years, Susan had been trying to hunt down the doctor, convinced he was the serial killer known as 'Splinter.' Someone is playing a cruel game with her, and they've only just begun.

Desperate to speak to the twelve victims rescued from the locked therapy rooms, Susan finds herself faced with a wall of silence. Why won't they talk?

Battling her demons while confronting the toughest case she's ever had to solve, Susan discovers a chilling truth about the true nature of Splinter – a killer preying on those seeking therapy.

But that's not all she finds...

She's about to uncover the shocking secret behind her husband's death – one that links him to the Splinter case.

With her family's safety hanging in the balance and her career on the line, can Susan protect her precious daughter and prevent a new killing spree before it's too late?

A totally addictive and heart-stopping page-turner that will have fans of Robert Dugoni, Charlie Donlea and Lisa Regan reading late into the night.