It might be because they want to find Diana's mother?
"Why don't you ask Louis about it? He can give a better explanation about this matter than my Ica. After all, he's the one who asked us to help him in this." Reuben stated looking at his cousin brother.
Everyone smiled at her bossy behaviour but it soon changed into worry when they heard a loud scream which terrified them all in a mere fraction of second, "Ahhhhhhhh...…."