Beckinsale mentioned that she actually didn't want to make this one at first. At first she thought this trilogy was over. Until the screenwriter Ren Wiseman told her the story of the fourth part, Beckinsale fell in love with him, so he decided to continue to play the fourth part.
Beckinsale did not want her daughter to play her daughter again in the film. When casting the role of her daughter in the film, Len Wiseman said that he found a particularly suitable girl. Without knowing it, Beckinsale ran into a girl who looked very much like him when he was visiting the bookstore, and found out that this was the girl Wiseman was talking about, India Eisley! So she was naturally selected into the crew.
One of the two directors directed for one day, and the other did not say a word while the other directed.
