Locky was a mutant.
Kestrel didn't know how Locky came to live in her house.
After her parents passed away, Kestrel was sent to live in the Tower, leaving the home empty. The staff had left, leaving the big yard vacant and locked.
Only when she came of age was Kestrel allowed to leave the Tower and return home.
When she first entered the house, she found the gate rusty and covered with wild grass. The main building, five stories high, and the smaller buildings were in the darkness, looking like a haunted house.
But once inside, she found it wasn't as dusty or spiderweb-filled as she had imagined. Instead, many corners seemed to have been cleaned regularly, leaving subtle signs of life.
Kestrel, alone with her luggage, walked through the dark house, exploring each room.
Having left when she was very young and greatly shocked, she no longer remembered her childhood here.