The Pigs and Birds return to Earth, but the Pigs have brought home their alien allies. These allies have a Time Machine, which they use. The Birds try to shut it down, and the aliens are trapped. However, there is a spillage of time energy. The Pigs and Birds are now capable of Time Travel. The Bad Piggies travel Back in Time, and find themselves near Pig-Like Dinosaurs and Primitive Birds, one of which joins the Flock as a replacement for Terrence, who has disappeared. They go forward in time, and find another Red who also joins the Flock. The Ice Bird and the Blue Birds have been combined, so a Green Ice Bird has two Blue Birds come out of him. Chuck has become superman-like. Bubbles has been turned backwards, so he goes from big to small. Bomb can now create ruptures in space-time, and Mighty can remove things completely from the fabric of existence. The Pigs have built spheres, each containing a fragment of the space-time continuum, which the birds start to destroy. Some Pigs now have different ages, and the King Pig has three versions just like Red. The Helmet Pig goes back in Time and removes the birds from existence, and a new timeline is created where the birds didn't exist. This backfires when the Eggs don't exist either, and the Pigs have no Eggs. The Helmet Pig fixes the timeline. The Moustache Pig does something very similar, but tries to make it so that the Birds never realised their eggs were gone. This fails. The Freckled Pig makes it so the birds never got to space. This works perfectly, and in the new timeline the Pigs have a vast space empire.