Busō Renkin Odcinek 12: Carnival

In the forest outside of Ginsei City, Bravo, Kazuki, and Tokiko decide to infiltrate the LXE hideout and take down the LXE before they can revive the Warrior Traitor, but they find the place empty except for Moonface, who explains that Dr. Butterfly has left for Ginsei High to use the school's students as sacrifices to revive the Warrior Traitor. Bravo stays behind to deal with Moonface, and Kazuki and Tokiko rush back to school, only to have their path blocked by a mysterious fog. With the fog-covered school isolated from the outside world, hordes of humanoid homunculi prepare to attack the students.