Princess Luna marches against the Factory with the remains of the Royal Guard...

How fickle are those with nothing to lose...

Some ponies were made for walking...

A final moment of rest.

An iron heart, born of worlds lost to death, beating into infinity. Harvesting evermore, unstoppable and unkillable. Expanding… Growing… Evolving...

The Princess has ruled for longer than anypony can remember, her word is final, and she is never wrong. But... What happens when she is? How far can one fall after a mistake centuries in the making?

Twilight gets to talk to an alien. It's all downhill from there.