Ambrose Bancroft returns to London society with his younger sister, hoping they'll leave ghosts of memory behind. They have only each other left. While Ambrose attempts to draw Mattie out, dragging her to balls and threatening to seek suitors for her, his sister recoils from his meddling. Finally, when Ambrose compels her to attend art class before she's ready, Mattie paints something horrific enough to banish them from society in public disgrace.
At Linwood Manor, Mattie and Ambrose aren't as alone as they think. Taking advantage of Mattie's desperate need to find freedom, a vanishing room lures Ambrose's sister into an illusory paradise. When Ambrose vows to get his sister back, by force if necessary, he finds himself up against an otherworldly power bent on her destruction and Mattie's bitterness turned to hatred.
When Mattie commits the ultimate betrayal, Ambrose realizes he never stopped protecting her long enough to learn what she really wanted. Despite her rejection, Ambrose tries to reconcile with Mattie, hoping for a second chance to be brother and sister. But before he learns to let her go, Ambrose is broken in body and mind, far beyond his capacity to endure.
When the dust settles, will Mattie be lost to him forever? Will Ambrose be the last of the Bancrofts?