The CEO of global energy conglomerate Greenleaf Oil has just discovered a terrifying secret: the planet only has a decade or less of petroleum left before it's gone forever. But he has a plan to make sure his great-great grandchildren can continue to generate maximum shareholder value ? and secure his own legacy in the process. Rather than develop a game-changing renewable energy source through the power of corporate innovation, Greenleaf has perfected the next best thing ? time travel (duh) ? so that a team of six field-rat contractors armed to the teeth in individually customized mech suits can go back to the Cretaceous Period, tweak the trajectory of the meteor that killed the dinosaurs, and give mankind another 500 millennia worth of oil reserves. What could go wrong? Only all of human history, of course ? because when Greenleaf's team of Tankers come home, they'll discover that not only did the dinosaurs never die out, they?ve kept evolving for another 60 million years...and they?re more pissed off than ever.