300 years ago, in a different timeline of Mewni' s history, Queen Eclipsa Butterfly gives birth to the true biological daughter of her and her Mewman husband, King Shastacan, Princess Andromeda Butterfly. A few years after the birth of her pure Mewman daughter, Eclipsa is imprisoned for eloping with her monster husband, leaving her young daughter to be instilled with a hatred for all monster kind. This hatred boils over into her teenage years when she is practicing magic of her own. ~ In another timeline of Mewni, Queen Star Butterfly and Queen Jackie have twin children of their own, Princess Rain Butterfly and Prince Lake Butterfly. The two grow up actually surrounded by monster's and grow up creating many monster friends, not including the ones who are royalty. Lake has no intention in being the next heir to Mewni's throne but out of him and Lake, he's the only one with strong magic abilities. Rain does try to get better at her magic but sadly she has no skills with the treasured family heriloom. Lake tries to coach his twin sister by giving her his wand, but no matter what they do, Rain's magic never seems to get any stronger. ~ When Andromeda manages to find multiple timelines where not only are monsters allowed in Mewni, but the Butterfly family has monsters in it, what will Rain and Lake do to protect the monster friends of their own?