Soul Eater Vol. 12 (manga)

The DWMA student body is still reeling after the news that one of their own is a witch. But as one young witch flees Death City, another has come back to DWMA hoping to strike a deal with Shinigami-sama. Medusa has already proven herself a traitor to the school, but the information she offers is critical to DWMA’s efforts to take down Arachnophobia and curb the spread of madness. Can Medusa be trusted to lead a team of students into the heart of enemy territory?!