Star throws her wand by accident and it ends up in the mouth of a growling dog who refuses to let it go. She has to take care of the dog and find its owner. Meanwhile, Marco struggles to get a straw into his juice box and has to take care of the laser puppies. She eventually discovers the dog named Willoughby is actually a extra-dimensional being who didn't like life on her planet, so Star has her adopted by a strange lady named Lydia.
After having skirmished with a number of dangerous monsters, Star Butterfly arrives on Earth to live with the Diaz family. However, rather than living a normal life, Star continues on having to battle villains both throughout the universe and in their high school, although if only to protect her extremely powerful wand, an object which she is still confused with.