In a manor by the sea, twelve sisters are cursed.

Annaleigh lives a sheltered life at Highmoor with her sisters. But loneliness fills the grand halls now that four of the girls' lives have been cut short, each death more tragic than the last.

Disturbed by a series of ghostly visions, Annaleigh becomes increasingly suspicious that her sisters' deaths were no accident. The girls have been sneaking out every night to attend glittering balls, dancing until dawn in silk gowns and shimmering slippers. Annaleigh isn't sure whether to try to stop them or to join their forbidden trysts. Because who – or what – are they really dancing with?

As Annaleigh's involvement with a mysterious stranger intensifies, it's a race to unravel the darkness that has enveloped her family – before it consumes her too.