Just when it seems the tragedy of Sablier is on the verge of recurring at Isla Yura's residence, the sinister blade of the Headhunter swings once more. From the darkness where the mysteries of Fianna's House and Humpty Dumpty converge, one truth will come to light: an unmoving reality that is itself so shocking, it seems like an illusion...Will Oz and his allies ever recover?

The air of celebration surrounding fifteen-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. Now that the relentless cogs of fate have begun to turn, do they lead only to crushing despair for Oz, or is there some shred of hope for him to grasp on to?

Having returned from the infernal Abyss only to find his whole world changed, young "sinner" Oz Vessalius embarks on an attempt at normalcy after being reunited with his best friend and valet, Gilbert, whom he had presumed dead. But during a trip into town with Gil and Alice, an unexpected encounter leads Oz down memory lane...For Oz, however, the path is one covered with the most menacing of thorns. And lying in wait to assail him there...The baleful eye of his father and the echoes of cursed words Oz would much rather forget...

A century before, in Sablier, a forbidden portal was flung wide by a boy, Vincent, in his single-minded desire to protect his brother, Gilbert. And thus did that foolhardy desire lead to the corruption of that innocent boy's soul like a sweet poison... Now, as Gil, Oz, and Alice wander the ruins of the former capital, they are assaulted by illusions from the past. But how much of it is real? And how much of it illusion?

Guided by Jack Vessalius, the man from Alice's memories, Oz wanders back into the world of lost memories in search of Alice. There, he stumbles upon the devastating tragedy of Sablier, the century-old disaster which sent the old capital into the Abyss, an incident of which no one has any recollection...except Alice, who was there?! When Oz discovers the truth of the memories Alice so desperately wants to forget, the powers of the B-Rabbit will spiral out of control and threaten the lives of all who are trapped within the dreamlike dimension, including Alice herself...

The incuse on Oz Vessalius's chest ticks onward, but the young heir to one of the four great dukedoms directs his gaze back, seeking the facts behind a centuries-old tragedy. Intent on examining the ruins of Sablier despite warnings to scare him away, Oz and his makeshift party of explorers wander through the remnants of the former capital in search of clues to shed light upon the consuming darkness of the past. But in the yawning void where the opulent city once stood, will Oz come face-to-face with the truth? Or will he find misery the only resident...?