After the death of her beloved grandfather on her twelfth birthday, Ebony Smart's world is turned upside down. Orphaned for a second time, she is sent to Dublin to live with her weird Aunt Ruby, with only her pet rat, Winston, for company. With every window nailed shut and a mysterious locked room, 23 Mercury Lane is brimming with secrets. Warned against entering by a voice in the shadows, Ebony is fearful for her future, but has no idea how much her life is about to change.

Aunt Ruby informs Ebony that she is part of the Order of Nine Lives - a special tribe of people who reincarnate. She claims Ebony has one week to break a terrible curse or else die – and if she fails, the future of the Order of Nine Lives, and her family, is at risk. With so much at stake, Ebony discovers it's difficult to trust – especially when there's somebody else trying to race her to the finish. Does she have what it takes to succeed when nothing is what it seems?