[1] Since then he has written novels for both adults and children, the latter often with frequent collaborator James Patterson.

[1][3] He has subsequently written more books in this series, called a "mash-up of Jersey Shore, Big Brother, and Survivor.

"[4] Grabenstein has also written many novels for children, including the Agatha and Anthony award-winning Haunted Mysteries series and the New York Times bestselling Escape from Mr. Lemoncello's Library.

He has also co-authored a number of books with author James Patterson, for whom he previously worked when he was in advertising.

[5] Grabenstein has won the Agatha Award for Best Children's/Young Adult Novel four times: for The Crossroads, The Hanging Hill, The Black Heart Crypt, and Escape From Mr. Lemoncello's Library.