Hundreds of asteroid rock-ships have landed on New York City, each one containing the embryo of a Menosuar that becomes full grown, and dangerous, on entering Earth’s atmosphere. Manhattan Island has turned into a Jurassic underworld where dinosaurs roam the sidewalks, and a Grandidierite force field rages in a green aurora borealis above the city. Lieutenant RainHorn and his men are powerless to stop this alien prehistoric invasion, and he has called in an expert, Ruby Stark, a palaeontologist.

Rex becomes a new protégé to a surprising bunch of historically remarkable men, involved in theories of space and time, and the discovery of dinosaurs. He will use their knowledge to continue fighting the dark forces that the Mantoids have unleashed on planet Earth. The Mantoids are sucking Lieutenant RainHorn’s Marines into collapsing black holes through their gaping jaws, and driving Tyrann’s Menosaurs to take refuge on Mars. From here, Tyrann hopes to regroup and try again to save his son, Tarock. But Mars is an inhospitable planet, and the Menosuar army grows daily weaker. King Tricerra holds council, and it is decided that a life giving asteroid should be sent from Prehistoria to explode with life on Mars, and save Trona’s Menosaur army.

When Rex discovers space time dimensions, he learns that time is not linear in its current form. Battling with dimension time travel, Rex realises that he has to journey out of this world and to the beginning of time. But how will he destroy the evil Mantoids’ dark energy, and still hold the balance of the universe in place? For when dark matter is removed, what will fill its place in the galaxy? It’s a decision he will have to wait to make, as New York spirals into dinosaur chaos, and zero gravity threatens human life.