Following the events of "The Hidden Truth", the universe as everyone knew it has changed. Mewni is now a large, metropolitan utopia and home to the advanced wielders of magic-powered technology. Star Butterfly and many of those she once knew are different people who know nothing of the reality that once was. Follows Star as she attempts to reclaim her past.

Following 'Battle for Mewni', Star and Marco carry on and work through new wrinkles in their friendship. Meanwhile, an unfrozen Eclipsa Butterfly seeks contentment in a new, unforgiving age. Centuries-old secrets which left scars on the Butterfly family's history are starting to unravel. As the the long-hidden truth is finally uncovered, sooner or later someone will have to pay.