The speculation about Officer Wang being the final boss was, of course, a joke.
Crayon drawing, a window, a little girl... Li Ang stared at the drawing, squinting as he pondered for a moment. The window in the drawing is a cross-pane window with a brown wooden frame and clear glass, whereas the windows in this room are a pair of casement windows with silver metal frames and gray frosted glass. There's only one place where the color is the same...
The latch pin.
Li Ang returned to the window. Each of the two casement windows had a latch pin. The left window's latch pin was intact. The right one, however, was rusted, its top half missing. This broken latch was cunningly hidden, its base stuck fast.
The shapes of the left and right latch pins are different. The left latch pin is a standard L-shaped metal cylinder, while the tip of the right one is circular on the outside and hollow inside, indented into a regular hexagon. It resembles a Hex Screwdriver.
