An alien spacecraft plummets to Earth, passing between the twin towers of the World Trade Center and coming to rest in Central Park. Two very different aliens survive, an Oinn and a Blettr, seemingly the bitterest of enemies, one captor, one captive. But when battle fleets from both races converge on Earth, it is discovered that the two races are in league, their plan: to invade Earth.

It is left to Colonel Rob Hayward to plan the defence of the planet, with the Russians his allies against this outside threat.