Deep In The Ocean | Stiles Stilinski

Kathrine, or Katy as she goes by, and her little brother James are new to the town Beacon Hills. They also have a secret. They are both mermaids. The prince and princess of Atlantis, to be exact. But they've just escaped from the beautiful underwater kingdom, after their Aunt Seraphina attacked.
Katy always knew about the other supernatural, she had to as she was supposed to be the next Queen, but how will she react when she finds out her new home is infested with them.
And how the McCall pack react to the new strange siblings?

Allison is alive
Isn't set in a certain season