"Oh God," said the policeman, turning white with fear. "It's coming this way!"
He's big, he's moody, he has a tail that could crush the Houses of Parliament… and he's all that stands between the Earth and total destruction. (Oh, and he's actually pretty nice, razor-sharp car-sized teeth notwithstanding). TIM (that's Tyrannosaur: Improved Model) is the product of a top secret military experiment. He lives in a comfy secret bunker buried deep beneath London's Trafalgar Square – but now the British government has decided he's too expensive to keep, and Tim must make a break for it.
He forms an unlikely alliance with fourteen-year-old Chris and his classmate, Anna, in order to save humanity from the greatest threat it has ever known: Anna's father, the brilliant but demented Professor Mallahide and his growing swarm of vicious nanobots.
The stage is set for a spectacular showdown the likes of which London has never seen. Who will prevail? The terrifying Professor Mallahide, or TIM, DEFENDER OF THE EARTH…?