Two powerful aliens from two different planets in the Milky Way galaxy have been transported to Earth's past to help avoid the cataclysmic events that were foreseen to lead to World War III. This would then ultimately lead to Earth's annihilation. In addition, a third planet in the Milky Way galaxy is set to take advantage of Earth's misfortunes and claim Earth for its own, when it develops the technology to travel faster than the speed of light. On another note, dinosaurs have snuck onto Earth!