Eight months after Cooper Cobb and Delilah Carney ended the Knock Knock Killer's murderous rampage and discovered the truth of his identity, a new killer has emerged.

Cooper and Delilah, along with their best friend, Riley must fight for their lives as a new killer takes on a more violent, gruesome and sadistic approach to taking them down.

Will they discover the truth and end the murders for good?

Reviews:

"I read this book much quicker than Knock, Knock. I am so involved in the storyline and it keeps me wanting more. I loved every bit of it. Can't wait to the concluding book."

"Who's There? Is Stevens second book in the Knock Knock Series and what a perfect follow up! This book is filled with action and mystery from the beginning to the very end! Steven does a phenomenal job keeping you on the edge of your seat in suspense as Cooper, Delilah, and Riley find themselves in the killers dangerous web. Every page leaves you craving more as you dive into what motivates each character and find out what is on the line in the event of failure. Find out if there is finally hope for the happy ending the readers are dying to see or if tragedy will continue to taunt Cooper and Delilah. Impatiently waiting for more from this author!!"

""Who's There?" Is the perfect follow up to Steven's first book, "Knock Knock." It followed a similar structure while still being different in its own right. It uses familiar characters from the first book in the series and further develops their personalities in a way that you feel like you know them. Great sequel!"