Allen Walker, a fifteen-year-old boy who roams the earth in search of Innocence, the mysterious substance used to create weapons to fight off demons, is washed away to unknown parts of the world after The Great Flood.
When Lenalee sets out to confront a Level 4 Akuma that's out to kill Komui, the Level 4 goes against the efforts of Lavi and Kanda and pursues its mission. Meanwhile, Allen is left to hold the line and finds it too much on his own.
As Krory becomes trapped in a seemingly hopeless situation, his comrades continue to traverse the Ark and encounter Tyki Mikk. As Tyki and Allen work out a truce, Lavi suspects that the Innocence is far more powerful than anyone can understand.
The Noah aid Lenalee, Lavi, and the others in their fight against the Millennium Earl's forces, but the agents of the Black Order refuse to give in, realizing that this may be the last stand of the Exorcists.
