A crossover with a superhero universe, for example, the Marvel Cinematic Universe. The kids from 'Race to Witch Mountain' could cross paths with the Avengers. They might need the Avengers' help to deal with an even more powerful enemy that is after the powers of the Witch Mountain aliens. This could lead to some really cool action scenes and interactions between the different characters.
One idea could be a crossover with another Disney adventure movie like 'Pirates of the Caribbean'. The characters from 'Race to Witch Mountain' could end up on a pirate ship while trying to escape some new threat related to their original mission. Maybe the aliens from Witch Mountain have some sort of power that the pirates are after.
Maybe an OC that is a young alien from a different planet than the ones in the movie. This OC could be trying to find a way back home while also having to deal with the chaos around Witch Mountain. They could form an unexpected alliance with the human characters and together face the various threats in the story. It would add a new dynamic to the existing plot.
Another plot could be a character from Stars Align getting lost and ending up near Witch Mountain. There, they encounter the beings from Race to Witch Mountain. They initially have some misunderstandings but then realize they need to work together. The character from Stars Align could introduce new ways of thinking to the Witch Mountain group, and they all strive to protect something important in the area.
One idea could be a crossover with 'Survivor'. Contestants from both shows could be combined in a new race where they have to use survival skills along with the regular race tasks. For example, building a shelter as part of a checkpoint.
Well, if it's a crossover with 'Star Wars', characters like Luke Skywalker could be added. He could use his Jedi skills to help the 'Race to Witch Mountain' characters in their journey. His knowledge of the Force might be useful against the enemies they face.
One idea could be to cross 'Every Witch Way' with 'Charmed'. The witches from 'Every Witch Way' could visit the Halliwell Manor and learn some new spells from the Charmed Ones. Maybe they could work together to defeat a powerful dark force that threatens both their worlds.
A crossover with 'Charmed' would also be great. The three Halliwell sisters and Sabrina could team up to fight a powerful dark force. They could exchange magical knowledge and learn from each other's different approaches to magic.
One idea could be a character who is tired of the rat race and decides to start a revolution within the corporate world. Another could be a group of friends in the rat race who discover a hidden treasure that changes their perspective on chasing wealth. Or perhaps a character who uses the chaos of the rat race to their advantage to achieve a personal dream that has nothing to do with money or status.
One common theme is adventure. Just like in the movie, the fanfictions often involve the characters going on exciting quests.
One idea could be that the main character discovers they have magical powers that are different from the witch's. For example, they can control time in a unique way while the witch mainly deals with nature magic. Another plot could involve the main character being adopted into a witch family and having to learn their ways to fit in, like attending a magical school for witches and warlocks where they face challenges from other students who are skeptical of an outsider joining. Also, perhaps the main character is adopted by the witch to fulfill a prophecy, and they have to figure out what that prophecy means and how to fulfill it while dealing with the normal struggles of growing up in a magical world.
Well, a plot could revolve around the witches going on an exchange program to a different, more modern magical school. This would lead to all kinds of cultural clashes and new friendships. Or perhaps a story where the teachers at the Worst Witch academy get turned into students for a day by a misfired spell, and Mildred and her friends have to teach them how to be proper students. A third idea could be that Mildred finds a magical creature that is lost and has to return it to its home, which is in a very dangerous and mysterious part of the magical world.