The story of each previous movie is quite simple, from where a sharknado comes, Fin (Ziering), his wife April (Reid) and others have to stop it. This film is trying to expand the concept to go beyond justifying by giving an old background story that characters can discover early (similar to Transformers: The Last Knight, a better film than this one). After all, this makes the plot more curvy, unreasonable, and not so important when the holes go from that point on.
Fin and the son of April Gil (Billy Barratt) caught a shark that they had to pursue the world and experience relationship problems along the way. There is also a secret society that is well-connected to women, for some reason, under the leadership of Nova Clarke (Scerbo), who is working to stop singing.