The song of the swan
(Book)

"Olga is an orphan and a thief, relying on trickery and sleight of hand to make her way in the world. But it's magic, not thievery, that could get her into trouble. When Olga and her partner-in-crime Pavel learn of a valuable jewel kept in a secluded castle, Olga sees an opportunity to change their lives: a prize so big, they'd never have to steal again. But the castle is not as it seems, ruled by an enchanter who hosts grand balls every night, only for the guests to disappear each morning, replaced by swans. Guided by cryptic clues from the palace spiders, Olga soon realizes she's in over her head-torn between a bargain with the enchanter, loyalty to Pavel, and determination to understand how the enchanted swans are linked to her own fate. One thing is certain: there is dark magic behind the castle's mysteries, and Olga will stop at nothing to unmask it"