Hearts of Pandora. Book 2. Volumes 3-4

Upon learning the terrible secret of the seal on his chest, Oz Bezaley does not succumb to despair. On the contrary, he decides to find out what happened ten years ago, and at the same time help Alice recover her lost memories. And Gilbert Nightray wants to protect Oz from danger at all costs, so he accompanies the Contract-bound pair everywhere. And then Vincent, Gil's blood brother, intervenes. Vincent, whose mere presence freezes the blood in one's veins...