You position yourself comfortably in the brown padded chair. As you gaze around the room, certain details catch your eye. To the left of the north door, a large dark gray rectangle hangs on the wall, at least two meters high but not even half a meter wide. Near it stands a large jointed wooden structure that clearly derives its ancestry both from coat racks and playground jungle gyms. It is about the size of a horse, but considerably less symmetrical.
After a few moments of examining the things on the floor, you also notice that even though there are boxes, crates, odd metal objects and unidentifiable pieces of equipment placed seemingly at random around the room, no furniture, box or other object touches more than one of the large wooden grid squares that make up the center part of the floor. All equipment and other items either rest on a single square, or are off the grid entirely (the latter is the case for the chair in which you sit).
The table next to you is also off the grid. It has carved legs that flare out at the base, and an old lace tablecloth draped over it that hangs halfway to the floor. On it sit several books in a stack.
The library is quite silent. None of the noises you heard from outside, including the music further south, penetrate into this room. However, after flipping through the stack of books for a while, you hear a whirring noise. After just a few seconds of the whirring growing louder, the north library door opens, and in comes a sort of low rolling metal cart, with a seagull riding on it.
The cart parks itself in front of the gray panel in the northwest corner, and starts clicking instead of whirring. The seagull, as calm as if this happens every day, flies the short distance to the horse-sized quasi-hatrack, which now reveals itself as an ideal bird perch. It commences studying you intently, shifting its wings occasionally.
Meanwhile, the cart has finished paying its respects to the Great Wall Deity, and it scoots out onto the grid toward one of the pieces of equipment. The cart's target is a boxy piece of metal bolted to the floor, with a pair of metal tracks leading away from the boxy piece until they cease abruptly at the edge of that particular wooden square. The cart fits perfectly between the tracks, and slides into and partially under the main shiny gray frame. There is an audible snapping sound, then a brief pause.
The piece of metal now demonstrates its utility as a cart-harness, as suddenly the wooden square begins rotating around a horizontal line down its middle, revealing a glimpse of darkness below the floor. The grid square flips 180 degrees, exposing a different motif on its other side, and the cart stays firmly in position as it disappears. The square, as smooth and polished on the bottom as it was on the top, aligns itself perfectly flush with the rest of the floor, and stops. After another brief pause, a more muffled snapping sound is heard, and the whirring sound below moves off to the west, dying away after a moment or two. The bird is disturbed by none of this.