The story begins with a night vigil at a Mortuary in Lion City, then spirals out of control in a Venetian luxury hotel called Padoli Palace.

A low-tier girl working at a morgue unexpectedly inherits a billion-dollar palace hotel in Venice. Yet she soon discovers that this dreamlike journey of class ascension is in fact a flesh-devouring trap orchestrated by quantum mechanics.

The story’s world-building is grounded in the idea that the universe operates according to the superposition principle of quantum physics. This sixteenth-century palace hotel is a forbidden zone with no seventh floor, its foundations built atop a colossal, unknown creature that devours everything—and the hotel itself is nothing but the monster's predatory camouflage.

As the protagonists delve deeper, they fall into the hotel’s non-existent "seventh floor"—which is, in truth, the monster's digestive tract…At this point, a life-or-death choice revolving around Schrödinger's Cat unfolds. Zoe is forced into a desperate gamble between two versions of herself: the wealthy but hypocritical self, and the destitute but genuine self. And the black cat will serve as the ultimate observer, deciding which reality collapses into existence.