The air of celebration surrounding 15-year-old Oz Vessalius's coming-of-age ceremony quickly turns to horror when he is condemned for a sin about which he knows nothing. He is thrown into an eternal, inescapable prison known as the Abyss from which there is no escape. There, he meets a young girl named Alice, who is not what she seems.
The past holds everyone in its thrall, and Oz, Alice, Raven, Break, and their acquaintances are no exception, especially as recollections of the tragedy of Sablier elude even those who were present. Indeed, with his own body playing host to Jack Vessalius, the hero of Sablier, the likelihood of Oz escaping the past seems nigh impossible. But given a renewed lease on life by Elliot Nightray - the legitimate heir to the Nightray dukedom, of all people - Oz is eager to keep moving forward by learning all that he can about the events that came to pass all those years ago. To this end, he and his friends seek an audience with another of the four great dukes - Duke Rufus Barma. But it is not a glimpse into a hundred-year-old disaster that is revealed to them in the Duke's presence, but rather one into Break's lamentable, shockingly unforgettable past...