When young tenant Xiaowen's cheap cat tree collapses and damages the floor, her uncle, Lu Gong, a master carpenter specializing in traditional Chinese architecture, decides to build a sturdy, eco-friendly solid-wood 'Cat Heavenly Palace' using traditional dougong brackets and mortise-and-tenon joinery. Facing scarce materials, the dangers of toxic, low-quality boards, and online skeptics questioning the load-bearing capacity of miniature components, the uncle and niece devote themselves to perfecting their craft and refuse to compromise. When a ferocious giant cat charges into the suspended eaves, this ancient intangible cultural heritage wisdom, which has protected grand halls and palaces for thousands of years, faces its ultimate real-world test, sparking a revolutionary breakthrough in traditional Chinese timber construction amid the hustle and bustle of modern city life.