The Autobots go in search of Cliffjumper, whose life signal is weak and find Megatron wielding the dangerous dark Energon.

Airachnid makes a deal with Silas to get revenge against Arcee and Jack.

The Autobots try to claim a magnetic weapon before the Decepticons get to it.

The Decepticons quickly try to build a space bridge before a prophesied darkness arrives.

Earth has an outbreak of natural disasters, caused by Dark Energon.

The Autobots acquire a surprising ally in their battle to save Earth.

The Autobots go to the Earth's core to fight for the planet; and Jack uncovers info about Optimus' background.