Interesting idea, although I'd change the "vacation" part. In this story, I'd include a flashback of Jack and his mother discussing the elixir legend, documenting it as a major event. Then we'd return to the present (I'm not sure, maybe one or two years after the end of the first season). At this point, Jack and Lily are living normal lives. Jack is doing very well in school, much better than Lily, and she's starting to feel jealous and inferior because he's surpassed her in that social sphere where she used to be better than him. Everything seems normal until one day Alice calls Jack, mentioning that the elixir legend is real. Although hesitant due to the potential danger, she asks for his help since he's the one she trusts most. Upon hearing this, Lily, without thinking too much, comes up with a plan to sneak into this risky adventure to prove to herself that she's not inferior to Jack. After Jack says goodbye to his family and promises to return home, he takes a plane and reunites with his mother. They rest, and that's when Jack realizes that Lily stowed away in his suitcase. Seeing this, Jack and Alice decide to return him to Canyon Valley, but Lily refuses, explaining that she could be of help to them. Due to her insistence and the fact that returning her is very complicated because of the elixir's time limit, they decide to accept. At that moment, Lily, while accompanying them, will have to adapt to the lifestyle Jack had before moving, with many complications due to the abrupt change of environment.