Arcs 17-21: Journey to Cybertron

After a long fiasco on Mobius in Megatron’s abscence, both sides gained and lost allies. With communications to Cybertron down, as well as the Space Bridge, the Autobots and Decepticons must return to Cybertron the long way around, going from Nebulos, to Animatros, to Velocitron, and to Gigantion along the way and settling affairs there.

Arc 17: Living Stories
Arc 18: Masters of Nebulos
Arc 19: Beast Wars!