In the aftermath of World War II in Berlin, a group of Nazi officers partake in a sinister ritual amidst the chaos of the city's destruction. Their goal is to resurrect the legendary Order of the 13 Lances, believed to bring about global annihilation. Fast forward to present-day Suwahara City in December, where Ren Fujii grapples with his recent hospitalization following a violent altercation with his friend Shirou Yusa. Plagued by recurring nightmares featuring a guillotine, murderous figures, and enigmatic knights, Ren yearns for a return to normalcy. However, Shirou's ominous warning about the city's residents losing their sanity lingers, casting a shadow over Ren's quest for peace.