Summary from Goodreads:
Final book of the series.
Cassie endures her darkest days under the rule of Balthazar. She finds a passage into the high tower, and comes face to face with the shadowy being whose presence has haunted her since her first days at the castle of La Falaise – and she makes an immense and horrifying discovery.
At the museum, the last survivors of a bleak existence are barely holding on. And the strange Order of Sister Celia make a chilling decision.
Someone very close to Ethan once told him, “When we can fight, we will fight, and when we can no longer fight, we will endure.”
With time running out, it is time to fight.
About the Author
Anya Allyn was born unexpectedly and without proper instructions.
A dreamy girl betwixt the clouds and space, she was given the thing she desired most for her tenth birthday–a microscope–and subsequently developed a penchant for small things: frogs and ants and microbes, and the earth (when viewed from other planets).
She considers a mind and body that do not roam free are the living dead.
Anya lives in a cottage by the sea–and slips in and out of forests and through a day, where the wild things are ….
She has four adventure-seeking boys and a bookcase filled with adventures. One day soon, she plans to head off on adventures of her own…