In season three, a giant-size Dome divides the town of Witwicky and traps the Decepticons inside, but it can't hold them forever. The Malto family and the Autobots must figure out a long-term solution, and help arrives from an unlikely place. While doing all they can to get life back to normal again, a mysterious saboteur threatens the Autobots, and Robby and Mo face a ruthless foe who challenges their right to wield the power of Quintus Prime.

Transformers: EarthSpark introduces a new generation of Transformers robots called Terrans - the first Transformers robots to be born on Earth - and together with the humans who welcome them in and care for them, they'll redefine what it means to be a family.