Jack has finally found the peace he has sought for so long.

Equestria, land of Friendship and Harmony, has finally brought his spirit peace and rest. Away from the darkness and tyranny of Aku, Jack has found a new strength and a renewed purpose that he could never have found in his world. The friends he has made gives him reason to smile. His desire to make sure Equestria does not follow a path like his world gives him purpose. And Applejack, his beloved, gives him a reason to live.

But the happiness does not last forever. And soon Jack will discover that it is not Aku that is the greatest foe that he has ever faced, but a foe that will take everything Jack's cares for and loves, despite all he does to combat it.

For this is a foe Jack has already beaten.