I'm trying to think up a good storyline for Transformers IV and couldn't, got all the way to an old discovery, found on mars left by decepticon ancestors to destroy all organic life in the galaxy so cybernetic life can thrive everywhere, countless systems free for control. It was called "The Flood."
Good luck Michael lol
only thing i could think about was somehow having some sort of artifact <liek that hasnt been done before> found on earth that sends a signal to Unicron, wich in turn sends him on a path to earth, thus revivng Megatron into Galvatron to ready the earth for its destruction by his new master.
buut prolly wont happen lol