The Empty Box and Zeroth Maria, Vol. 7 (light Novel)

In this final volume, Kazuki makes his last stand against O to fulfill his vow and bring back the "zeroth" Maria?-?the real Maria. The forces that stand between them seem insurmountable, and the trials they will have to overcome will be painful, but Kazuki has always had faith that there is no despair that can't be undone by believing in normal life. Will he and Maria be reunited? Or will they both be trapped forever?