At the Earth-Mewni Gardens, Hekapoo, a demon scientist who was working on a different kind of interdimensional travel, was with her husband, Oskar Greason, a musician, and their daughter, Ember Coanstella Greason. Ember had participated in battles and achieved many victories. But, like Twilight, Ember felt like her parents were being too overprotective of her, because she had asked them if she could visit other dimensions by herself, but Hekapoo always told her she might get lost on the way there. The two royal couples had made their way to the Earth-Mewni Gardens, where Hekapoo greeted them...
Hekapoo: Hello, Queen Star and King Marco, and the rulers of the Underworld. (laughs slightly) So, what can I do for you?
Marco: Well, H-Poo, we need to get to another dimension.
Janna: Mina Loverberry, apparently was sent to cause trouble in another world.
Star: Could you locate which world Mina and Manfred were sent to?
Hekapoo: Let me go to the map, and find out what world they're in.
As Hekapoo check on a computer map monitor about the whereabout of where Mina and Manfred went off to, Ember saw the prince and princess of Earth-Mewni run over near the Gardens.
Twilight: Ember! Did your mom find out where my parents' enemy is?
Ember: She's looking it up right now.
Nathaniel: Twilight wants to secretly follow our parents to prove to them she could be a responsible ruler.
Ember: I can relate to that. My mother doesn't want me visiting other dimensions unless she or my father is with me.
Twilight: I had thought we would all travel together to another dimension to join my parents against that enemy, to show we can we heroes, too.
Ember: (a little hesitant) Oh, I don't know about this, Twilight. I just don't fell comfortable not telling my parents where I am.
Twilight: But what if you instead showed your parents that you're independent?
Ember thought about that question. Nathaniel chimed in, 'We'll be by your side if things get too rough.'
The Dancer of Flames lit up...
Ember: Count me in! But we have to get on the ride in secret, so our parents don't see us.
The royal children and Ember then snuck onto one of the garden block rides, while Hekapoo had located where Mina and Manfred were...
Hekapoo: Queen Star, King Marco, Mina and Manfred have been found in a city called 'Adventure Bay.'
Oskar: That place sounds like it's pretty far away if you ask me.
Star: Before we go to Adventure Bay, we need to visit another world. There's a friend of ours there who's enemy there seems to be helping Mina out, and we might need help.
Hekapoo: What is the other world?
Marco whispered to Hekapoo what dimension they needed to go to first, and Hekapoo then found that dimension for the two royal couples...
Hekapoo: Here you are, a garden block that will help you get there quickly.
Marco: Thank you, H-Poo. Let's go, everyone!
The royal couples, plus Tom and Janna two sons, went to the traveling garden block, and Hekapoo then sent the block to where they wanted to go first. Unknown to everyone, Hekapoo's daughter Ember, and The Diaz's two children, Nathaniel and Twilight, had connected the garden block they were in onto the royal couples' garden block, meaning they would be joining them (secretly) on this journey.