About the book: year / Once upon a time, Koschey the Immortal, ruler of the Iron Kingdom, kidnapped Princess Mstislava from the Silver Kingdom. Polonyanka gave birth to two children: a boy Yaroslav and a girl Zoryana. Soon Mstislava died, taking an oath from her son not to serve Koshchei. 20 years later, the children receive an order from their father to kidnap Princess Gorlitsa, whom Koschey wants to marry. Brother and sister are faced with a choice: allow the girl to repeat the fate of their mother, or find allies to fight Koshchei. What will they choose??