The first book in the Dave Gurney series, Think of a Number is a heart-pounding game of cat and mouse that grows relentlessly darker and more frightening as its

Join TV Presenter, Johnny Ball for an incredible number-filled adventure, cracking secret codes and unravelling mazes Let your child join Johnny Ball on a dazzl

When an old colleague comes to him for help solving the mysterious death of his town's most prominent resident, retired NYPD detective Dave Gurney must use all

Consulting with a young documentary producer only to suffer a bizarre series of accidents shortly afterward, decorated NYPD detective Dave Gurney discovers link