The Iron King's Hands - Iain Grant - Bog

When Rose and Violet were brought to the orphanage as babies, no one knew where they had come from or who they truly were. But years later, something has come for Rose and carried her away. With only her horse and an automaton bear to help her, Violet must cross the sea to the Empty City and the castle of the Iron King and do battle with his mechanical army. But will she be able to rescue her sister?