Quod Erat Demonstrandum is a realm where the dead don’t rest—they work. In this otherworldly metropolis, reapers guide the recently deceased to the afterlife, navigating a bustling, high-end world that never sleeps. Xiao Li is new to this world, trying to make sense of it all while under the guidance of three seasoned reapers: Callum, Seo-Jun, and Sasaki. As they introduce her to the intricacies of QED, she discovers that time doesn’t flow here like it does in the living world, and each reaper's appearance and role are meticulously controlled. From processing fake identities to managing souls, the realm operates like a well-oiled machine—yet there’s a strange sense of community among its inhabitants. In QED, purpose isn’t lost after death; it’s redefined. But as Xiao Li adapts to her new life, she starts to see cracks beneath the polished surface. What happens when those who guide the dead can’t find peace themselves? And what secrets lie hidden in a company where time, life, and death are just parts of an endless cycle?