I didn't know if this continent even had hidden families existing or known, but I took a chance and, worst case scenario, I would move on.
"Yes, as you could see, my family has passed down rare crystal magic, and the reason we came here is because a member of our family, my younger sister, disappeared, during her coming of age ceremony."
I acted sad and heartbroken. I imagined one of the girls disappearing, and it would certainly be a serious issue, that thinking about it brought me more anger than anything, for not being able to do anything about it.
"Haaaa~!"
But then I calmed down. Well, I guess it worked, to give it more realism.
"Ehem... And the reason we're here is because he possesses a tracking device that guides us to the demonic side."
"..."
Well, everyone was seriously listening to my made-up explanation. I had time to think about it during the day and I thought it was perfect.