Z. rex is a dinosaur who has been recreated in the 21st century by a group of scientists. Modelled on a T. rex, Z. rex is the ultimate dinosaur with extreme power and strength. His brain was designed using the brainwaves of a boy called Adam, whose father Bill helped to created Z. rex whilst working on a video game project. After Z. rex escapes from his captivity at a laboratory, there is a raid on Adam and his father's apartment in Mexico. Bill gets taken away by a group chasing Z. rex and Adam and Z. rex are left alone. They go on a quest to find Bill with many unexpected occurrences along the way. This is a good book for 9 to 12-year-olds and deserves to be a big hit!