The castle of tangled magic

"Twelve-year-old Olia knows a thing or two about secrets. Her parents are the caretakers of Castle Mila, a soaring palace with golden domes, lush gardens, and countless rooms. Literally countless rooms. There are rooms that appear and disappear, and rooms that have been hiding themselves for centuries. The only person who can access them is Olia. She has a special bond with the castle, and it seems to trust her with its secrets. But then a violen...