Originally Posted by Golgo-13
So who repaired SS's arm from being ripped off in ROTF?
Probably his mom.
I think of the trilogy like this:
In the first one Megatron is already on Earth and Decepticons are searching for the AllSpark to revive him. Meanwhile, the Autobots are dealing with the live lambs from Lebanon being shipped out to people who didn't order them. Eventually Megatron meets up with Optimus Prime's stick and then meets his chalice. End of chapter one.
In ROTF, it is revealed that the Decepticon's are actually lead by one 'The Fallen' who basically wants to throw a stick into the Sun. Enter the aqua-lambs who come down through the tunnel, from the first one. From there Jet Fire tells Optimus "take my power and my spark and become the best selling action-figure yet." Almost instantly, The Fallen meets up with Prime's fist. End of ch. dos.
In DOTM, it is revealed that years ago, in the 1960's, when Megatron was all ready buried on Earth somewhere, he was actually still in space making a deal with Sentinel Prime to pull that pivotal lever. It can be assumed that he snuck back into the dam that was built around him, undetected. The Autobots want nothing to do with the shenanigans so they place a spider on Megatron's head. End of trilogy.