Cannibalism Part VI is the 50th chapter of the Bungou Stray Dogs manga.
Mori and Fukuzawa decide to settle the war once and for all and both go to a place that only they know. They both decide to end the war with a duel. Mori summons Elise. The scene cuts to a flash back, and it is revealed that the two knew each other in the past and that Fukuzawa even was ordered by someone to protect Mori. During the battle, Fukuzawa defeats Elise but Mori then stabs him. Back at the Agency, Kunikida tells Atsushi about his relationship with Katai and his past. He then tells Atsushi that Katai must be alive as he left something to indicate that someone saved him. Back at the battle, Fukuzawa lays on the ground bleeding to death. A cat suddenly appears at the scene. Mori is about to kill Fukuzawa when the ground suddenly shakes. The cat turns into none other than Natsume Souseki. Mori and Fukuzawa both gasp in shock. Katai suddenly appears and Natsume reveals that Katai has discovered the base of the Rats in the House of the Dead. Natsume then encourages Mori and Fukuzawa to prove to him that they won't let Fyodor destroy either organization.