The Dormant Volcano Mysteriously Erupts - S1.E12

While Ultra Magnus and Scattershot are investigating some strange seismic activity in Peru, the Cybertron Headmasters send Steeljaw and Ramhorn to find out what's inside the black nebula (from the last episode). Inside the nebula is a planet called Charr where enslaved Battle Beasts are used by Scorponok to build a massive construct.

In the Andes, a dormant volcano suddenly erupts, and the Protectobots and Trainbots are sent to rescue the people living nearby. They are confronted by the Predacons and the Destron Headmasters. The other Cybertrons use Broadsides to fly to Earth, drive off Predaking, and the Trainbots evacuate the humans.

In the nebula, Scorponok explains that the volcano exploded so the Destrons can tap its energies while Ramhorn and Steeljaw secretly listen. On Earth, the Destrons make one last attempt to take the villagers hostage, but they are thwarted by the Cybertrons. Back on Charr, Scorponok reveals part of his plans to Cyclonus and Scourge; Ramhorn and Steeljaw r